mb/*: Specify type of `VARIANT_DIR` once

Specify the type of the `VARIANT_DIR` Kconfig symbol once instead of
doing so on each and every mainboard.

Change-Id: Iea2f992a59e41e00fec3cdc9d6a13b5f3ab0a437
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56558
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/Kconfig b/src/mainboard/Kconfig
index dc02e98..8f9b48c 100644
--- a/src/mainboard/Kconfig
+++ b/src/mainboard/Kconfig
@@ -19,6 +19,9 @@
 config MAINBOARD_VENDOR
 	string "Mainboard vendor name"
 
+config VARIANT_DIR
+	string
+
 config BOARD_ROMSIZE_KB_256
 	bool
 config BOARD_ROMSIZE_KB_512
diff --git a/src/mainboard/amd/mandolin/Kconfig b/src/mainboard/amd/mandolin/Kconfig
index e0bf3e3..9d545b8 100644
--- a/src/mainboard/amd/mandolin/Kconfig
+++ b/src/mainboard/amd/mandolin/Kconfig
@@ -53,7 +53,6 @@
 	default "amd/mandolin"
 
 config VARIANT_DIR
-	string
 	default "mandolin" if BOARD_AMD_MANDOLIN
 	default "cereme" if BOARD_AMD_CEREME
 
diff --git a/src/mainboard/asrock/g41c-gs/Kconfig b/src/mainboard/asrock/g41c-gs/Kconfig
index ac58e38..7ae8461 100644
--- a/src/mainboard/asrock/g41c-gs/Kconfig
+++ b/src/mainboard/asrock/g41c-gs/Kconfig
@@ -26,7 +26,6 @@
 	default "asrock/g41c-gs"
 
 config VARIANT_DIR
-	string
 	default "g41c-gs-r2" if BOARD_ASROCK_G41C_GS_R2_0
 	default "g41c-gs" if BOARD_ASROCK_G41C_GS
 	default "g41m-gs" if BOARD_ASROCK_G41M_GS
diff --git a/src/mainboard/asus/h61-series/Kconfig b/src/mainboard/asus/h61-series/Kconfig
index 362546e..eeec4e7 100644
--- a/src/mainboard/asus/h61-series/Kconfig
+++ b/src/mainboard/asus/h61-series/Kconfig
@@ -18,7 +18,6 @@
 	default "asus/h61-series"
 
 config VARIANT_DIR
-	string
 	default "h61m-cs"          if BOARD_ASUS_H61M_CS
 	default "p8h61-m_lx"       if BOARD_ASUS_P8H61_M_LX
 	default "p8h61-m_lx3_r2_0" if BOARD_ASUS_P8H61_M_LX3_R2_0
diff --git a/src/mainboard/asus/p2b/Kconfig b/src/mainboard/asus/p2b/Kconfig
index 8f3eb67..d56efd2 100644
--- a/src/mainboard/asus/p2b/Kconfig
+++ b/src/mainboard/asus/p2b/Kconfig
@@ -37,7 +37,6 @@
 	default "P3B-F" if BOARD_ASUS_P3B_F
 
 config VARIANT_DIR
-	string
 	default "p2b" if BOARD_ASUS_P2B
 	default "p2b-d" if BOARD_ASUS_P2B_D
 	default "p2b-ds" if BOARD_ASUS_P2B_DS
diff --git a/src/mainboard/asus/p5qc/Kconfig b/src/mainboard/asus/p5qc/Kconfig
index 31ad4f3..c501b7a 100644
--- a/src/mainboard/asus/p5qc/Kconfig
+++ b/src/mainboard/asus/p5qc/Kconfig
@@ -19,7 +19,6 @@
 	default "asus/p5qc"
 
 config VARIANT_DIR
-	string
 	default "p5qc" if BOARD_ASUS_P5QC
 	default "p5q_pro" if BOARD_ASUS_P5Q_PRO
 	default "p5ql_pro" if BOARD_ASUS_P5QL_PRO
diff --git a/src/mainboard/asus/p5qpl-am/Kconfig b/src/mainboard/asus/p5qpl-am/Kconfig
index e54809c..2359e32 100644
--- a/src/mainboard/asus/p5qpl-am/Kconfig
+++ b/src/mainboard/asus/p5qpl-am/Kconfig
@@ -23,7 +23,6 @@
 	default "asus/p5qpl-am"
 
 config VARIANT_DIR
-	string
 	default "p5qpl-am" if BOARD_ASUS_P5QPL_AM
 	default "p5g41t-m_lx" if BOARD_ASUS_P5G41T_M_LX
 
diff --git a/src/mainboard/asus/p8x7x-series/Kconfig b/src/mainboard/asus/p8x7x-series/Kconfig
index 1e725b2..4ecb4b4 100644
--- a/src/mainboard/asus/p8x7x-series/Kconfig
+++ b/src/mainboard/asus/p8x7x-series/Kconfig
@@ -19,7 +19,6 @@
 	default "asus/p8x7x-series"
 
 config VARIANT_DIR
-	string
 	default "p8c_ws"      if BOARD_ASUS_P8C_WS
 	default "p8h77-v"     if BOARD_ASUS_P8H77_V
 	default "p8z77-m_pro" if BOARD_ASUS_P8Z77_M_PRO
diff --git a/src/mainboard/clevo/cml-u/Kconfig b/src/mainboard/clevo/cml-u/Kconfig
index d68e949..0452bc1 100644
--- a/src/mainboard/clevo/cml-u/Kconfig
+++ b/src/mainboard/clevo/cml-u/Kconfig
@@ -70,7 +70,6 @@
 	default n
 
 config VARIANT_DIR
-	string
 	default "l140cu" if BOARD_CLEVO_L140CU_BASE
 
 config SEABIOS_PS2_TIMEOUT
diff --git a/src/mainboard/clevo/kbl-u/Kconfig b/src/mainboard/clevo/kbl-u/Kconfig
index 93ddb82..0b2f0b0 100644
--- a/src/mainboard/clevo/kbl-u/Kconfig
+++ b/src/mainboard/clevo/kbl-u/Kconfig
@@ -35,7 +35,6 @@
 	default "clevo/kbl-u"
 
 config VARIANT_DIR
-	string
 	default "n13xwu" if BOARD_CLEVO_N130WU
 
 config MAINBOARD_PART_NUMBER
diff --git a/src/mainboard/gigabyte/ga-945gcm-s2l/Kconfig b/src/mainboard/gigabyte/ga-945gcm-s2l/Kconfig
index cb6325f6..bbf46f7 100644
--- a/src/mainboard/gigabyte/ga-945gcm-s2l/Kconfig
+++ b/src/mainboard/gigabyte/ga-945gcm-s2l/Kconfig
@@ -23,7 +23,6 @@
 	default "gigabyte/ga-945gcm-s2l"
 
 config VARIANT_DIR
-	string
 	default "ga-945gcm-s2l" if BOARD_GIGABYTE_GA_945GCM_S2L
 	default "ga-945gcm-s2c" if BOARD_GIGABYTE_GA_945GCM_S2C
 
diff --git a/src/mainboard/gigabyte/ga-b75m-d3h/Kconfig b/src/mainboard/gigabyte/ga-b75m-d3h/Kconfig
index d2c501e..643ed78 100644
--- a/src/mainboard/gigabyte/ga-b75m-d3h/Kconfig
+++ b/src/mainboard/gigabyte/ga-b75m-d3h/Kconfig
@@ -29,7 +29,6 @@
 	default "gigabyte/ga-b75m-d3h"
 
 config VARIANT_DIR
-	string
 	default "ga-b75m-d3h" if BOARD_GIGABYTE_GA_B75M_D3H
 	default "ga-b75m-d3v" if BOARD_GIGABYTE_GA_B75M_D3V
 	default "ga-b75-d3v" if BOARD_GIGABYTE_GA_B75_D3V
diff --git a/src/mainboard/gigabyte/ga-h61m-series/Kconfig b/src/mainboard/gigabyte/ga-h61m-series/Kconfig
index d9d7787..cec2c61 100644
--- a/src/mainboard/gigabyte/ga-h61m-series/Kconfig
+++ b/src/mainboard/gigabyte/ga-h61m-series/Kconfig
@@ -22,7 +22,6 @@
 	default "gigabyte/ga-h61m-series"
 
 config VARIANT_DIR
-	string
 	default "ga-h61m-s2pv" if BOARD_GIGABYTE_GA_H61M_S2PV
 	default "ga-h61m-ds2v" if BOARD_GIGABYTE_GA_H61M_DS2V
 	default "ga-h61ma-d3v" if BOARD_GIGABYTE_GA_H61MA_D3V
diff --git a/src/mainboard/google/auron/Kconfig b/src/mainboard/google/auron/Kconfig
index b1b4583..0d37a10 100644
--- a/src/mainboard/google/auron/Kconfig
+++ b/src/mainboard/google/auron/Kconfig
@@ -28,7 +28,6 @@
 	default "google/auron"
 
 config VARIANT_DIR
-	string
 	default "auron_paine" if BOARD_GOOGLE_AURON_PAINE
 	default "auron_yuna" if BOARD_GOOGLE_AURON_YUNA
 	default "buddy" if BOARD_GOOGLE_BUDDY
diff --git a/src/mainboard/google/beltino/Kconfig b/src/mainboard/google/beltino/Kconfig
index fadb718..8ecba7a 100644
--- a/src/mainboard/google/beltino/Kconfig
+++ b/src/mainboard/google/beltino/Kconfig
@@ -23,7 +23,6 @@
 	default "google/beltino"
 
 config VARIANT_DIR
-	string
 	default "mccloud" if BOARD_GOOGLE_MCCLOUD
 	default "monroe" if BOARD_GOOGLE_MONROE
 	default "panther" if BOARD_GOOGLE_PANTHER
diff --git a/src/mainboard/google/brya/Kconfig b/src/mainboard/google/brya/Kconfig
index 00d607c..80e8d72 100644
--- a/src/mainboard/google/brya/Kconfig
+++ b/src/mainboard/google/brya/Kconfig
@@ -75,7 +75,6 @@
 	default "Taeko" if BOARD_GOOGLE_TAEKO
 
 config VARIANT_DIR
-	string
 	default "brya0" if BOARD_GOOGLE_BRYA0
 	default "primus" if BOARD_GOOGLE_PRIMUS
 	default "gimble" if BOARD_GOOGLE_GIMBLE
diff --git a/src/mainboard/google/cyan/Kconfig b/src/mainboard/google/cyan/Kconfig
index b237c21..9640489 100644
--- a/src/mainboard/google/cyan/Kconfig
+++ b/src/mainboard/google/cyan/Kconfig
@@ -41,7 +41,6 @@
 	default ""
 
 config VARIANT_DIR
-	string
 	default "banon" if BOARD_GOOGLE_BANON
 	default "celes" if BOARD_GOOGLE_CELES
 	default "cyan" if BOARD_GOOGLE_CYAN
diff --git a/src/mainboard/google/dedede/Kconfig b/src/mainboard/google/dedede/Kconfig
index ac77b69..3cf1a3a 100644
--- a/src/mainboard/google/dedede/Kconfig
+++ b/src/mainboard/google/dedede/Kconfig
@@ -124,7 +124,6 @@
 	default 2
 
 config VARIANT_DIR
-	string
 	default "boten" if BOARD_GOOGLE_BOTEN
 	default "boten" if BOARD_GOOGLE_BOTEN_LEGACY
 	default "dedede" if BOARD_GOOGLE_DEDEDE
diff --git a/src/mainboard/google/deltaur/Kconfig b/src/mainboard/google/deltaur/Kconfig
index 7ce87cf..7ed70ac 100644
--- a/src/mainboard/google/deltaur/Kconfig
+++ b/src/mainboard/google/deltaur/Kconfig
@@ -73,7 +73,6 @@
 	default 2
 
 config VARIANT_DIR
-	string
 	default "deltan" if BOARD_GOOGLE_DELTAN
 	default "deltaur" if BOARD_GOOGLE_DELTAUR
 
diff --git a/src/mainboard/google/drallion/Kconfig b/src/mainboard/google/drallion/Kconfig
index 8316e9b..55f203e 100644
--- a/src/mainboard/google/drallion/Kconfig
+++ b/src/mainboard/google/drallion/Kconfig
@@ -75,7 +75,6 @@
 	default 0 if BOARD_GOOGLE_DRALLION
 
 config VARIANT_DIR
-	string
 	default "drallion" if BOARD_GOOGLE_DRALLION
 
 config DEVICETREE
diff --git a/src/mainboard/google/fizz/Kconfig b/src/mainboard/google/fizz/Kconfig
index 5153441..b7a6a62 100644
--- a/src/mainboard/google/fizz/Kconfig
+++ b/src/mainboard/google/fizz/Kconfig
@@ -69,7 +69,6 @@
 	default 64  # GPE0_DW2_00 (GPP_E0)
 
 config VARIANT_DIR
-	string
 	default "fizz" if BOARD_GOOGLE_FIZZ
 	default "karma" if BOARD_GOOGLE_KARMA
 	default "endeavour" if BOARD_GOOGLE_ENDEAVOUR
diff --git a/src/mainboard/google/glados/Kconfig b/src/mainboard/google/glados/Kconfig
index 144dee3..cd553ff 100644
--- a/src/mainboard/google/glados/Kconfig
+++ b/src/mainboard/google/glados/Kconfig
@@ -50,7 +50,6 @@
 	default "Google_Glados"
 
 config VARIANT_DIR
-	string
 	default "asuka" if BOARD_GOOGLE_ASUKA
 	default "caroline" if BOARD_GOOGLE_CAROLINE
 	default "cave" if BOARD_GOOGLE_CAVE
diff --git a/src/mainboard/google/guybrush/Kconfig b/src/mainboard/google/guybrush/Kconfig
index fa00c76..17cdada 100644
--- a/src/mainboard/google/guybrush/Kconfig
+++ b/src/mainboard/google/guybrush/Kconfig
@@ -102,7 +102,6 @@
 	default 1          # 33.33 MHz
 
 config VARIANT_DIR
-	string
 	default "guybrush" if BOARD_GOOGLE_GUYBRUSH
 
 config DEVICETREE
diff --git a/src/mainboard/google/hatch/Kconfig b/src/mainboard/google/hatch/Kconfig
index 947f816..f11c689 100644
--- a/src/mainboard/google/hatch/Kconfig
+++ b/src/mainboard/google/hatch/Kconfig
@@ -143,7 +143,6 @@
 	default 53 # GPE0_DW1_21 (GPP_C21)
 
 config VARIANT_DIR
-	string
 	default "akemi" if BOARD_GOOGLE_AKEMI
 	default "dratini" if BOARD_GOOGLE_DRATINI
 	default "duffy" if BOARD_GOOGLE_DUFFY
diff --git a/src/mainboard/google/jecht/Kconfig b/src/mainboard/google/jecht/Kconfig
index dc25f190..42be86a 100644
--- a/src/mainboard/google/jecht/Kconfig
+++ b/src/mainboard/google/jecht/Kconfig
@@ -22,7 +22,6 @@
 
 
 config VARIANT_DIR
-	string
 	default "guado" if BOARD_GOOGLE_GUADO
 	default "jecht" if BOARD_GOOGLE_JECHT
 	default "rikku" if BOARD_GOOGLE_RIKKU
diff --git a/src/mainboard/google/kahlee/Kconfig b/src/mainboard/google/kahlee/Kconfig
index 3128493..5940d1a 100644
--- a/src/mainboard/google/kahlee/Kconfig
+++ b/src/mainboard/google/kahlee/Kconfig
@@ -47,7 +47,6 @@
 	default "3rdparty/blobs/mainboard/google/kahlee/VBIOS_015_049_000_017.bin"
 
 config VARIANT_DIR
-	string
 	default "aleena" if BOARD_GOOGLE_ALEENA
 	default "careena" if BOARD_GOOGLE_CAREENA
 	default "grunt" if BOARD_GOOGLE_GRUNT
diff --git a/src/mainboard/google/mancomb/Kconfig b/src/mainboard/google/mancomb/Kconfig
index 1a247e7..1e809ad 100644
--- a/src/mainboard/google/mancomb/Kconfig
+++ b/src/mainboard/google/mancomb/Kconfig
@@ -84,7 +84,6 @@
 	default 1          # 33.33 MHz
 
 config VARIANT_DIR
-	string
 	default "mancomb" if BOARD_GOOGLE_MANCOMB
 
 config DEVICETREE
diff --git a/src/mainboard/google/octopus/Kconfig b/src/mainboard/google/octopus/Kconfig
index 4caf5a0..eb6cbc6 100644
--- a/src/mainboard/google/octopus/Kconfig
+++ b/src/mainboard/google/octopus/Kconfig
@@ -52,7 +52,6 @@
 	default "google/octopus"
 
 config VARIANT_DIR
-	string
 	default "yorp" if BOARD_GOOGLE_YORP
 	default "phaser" if BOARD_GOOGLE_PHASER
 	default "fleex" if BOARD_GOOGLE_FLEEX
diff --git a/src/mainboard/google/poppy/Kconfig b/src/mainboard/google/poppy/Kconfig
index 74be527..f4be0c5 100644
--- a/src/mainboard/google/poppy/Kconfig
+++ b/src/mainboard/google/poppy/Kconfig
@@ -114,7 +114,6 @@
 	default 64  # GPE0_DW2_00 (GPP_E0)
 
 config VARIANT_DIR
-	string
 	default "atlas" if BOARD_GOOGLE_ATLAS
 	default "poppy" if BOARD_GOOGLE_POPPY
 	default "nami" if BOARD_GOOGLE_NAMI
diff --git a/src/mainboard/google/rambi/Kconfig b/src/mainboard/google/rambi/Kconfig
index 2c1b040..983ca49 100644
--- a/src/mainboard/google/rambi/Kconfig
+++ b/src/mainboard/google/rambi/Kconfig
@@ -27,7 +27,6 @@
 	default "google/rambi"
 
 config VARIANT_DIR
-	string
 	default "banjo" if BOARD_GOOGLE_BANJO
 	default "candy" if BOARD_GOOGLE_CANDY
 	default "clapper" if BOARD_GOOGLE_CLAPPER
diff --git a/src/mainboard/google/reef/Kconfig b/src/mainboard/google/reef/Kconfig
index d1de54f..9fee4a5 100644
--- a/src/mainboard/google/reef/Kconfig
+++ b/src/mainboard/google/reef/Kconfig
@@ -49,7 +49,6 @@
 	default "google/reef"
 
 config VARIANT_DIR
-	string
 	default "reef" if BOARD_GOOGLE_REEF
 	default "pyro" if BOARD_GOOGLE_PYRO
 	default "sand" if BOARD_GOOGLE_SAND
diff --git a/src/mainboard/google/sarien/Kconfig b/src/mainboard/google/sarien/Kconfig
index 1398292..383436a 100644
--- a/src/mainboard/google/sarien/Kconfig
+++ b/src/mainboard/google/sarien/Kconfig
@@ -77,7 +77,6 @@
 	default 2
 
 config VARIANT_DIR
-	string
 	default "arcada" if BOARD_GOOGLE_ARCADA
 	default "sarien" if BOARD_GOOGLE_SARIEN
 
diff --git a/src/mainboard/google/slippy/Kconfig b/src/mainboard/google/slippy/Kconfig
index c69a73a..7bb717b 100644
--- a/src/mainboard/google/slippy/Kconfig
+++ b/src/mainboard/google/slippy/Kconfig
@@ -30,7 +30,6 @@
 	default "google/slippy"
 
 config VARIANT_DIR
-	string
 	default "falco" if BOARD_GOOGLE_FALCO
 	default "leon" if BOARD_GOOGLE_LEON
 	default "peppy" if BOARD_GOOGLE_PEPPY
diff --git a/src/mainboard/google/volteer/Kconfig b/src/mainboard/google/volteer/Kconfig
index e26070f..73fe6c7 100644
--- a/src/mainboard/google/volteer/Kconfig
+++ b/src/mainboard/google/volteer/Kconfig
@@ -128,7 +128,6 @@
 	default 21  # GPE0_DW0_21 (GPP_C21)
 
 config VARIANT_DIR
-	string
 	default "delbin" if BOARD_GOOGLE_DELBIN
 	default "eldrid" if BOARD_GOOGLE_ELDRID
 	default "halvor" if BOARD_GOOGLE_HALVOR
diff --git a/src/mainboard/google/zork/Kconfig b/src/mainboard/google/zork/Kconfig
index a9ca5da..e93516e 100644
--- a/src/mainboard/google/zork/Kconfig
+++ b/src/mainboard/google/zork/Kconfig
@@ -64,7 +64,6 @@
 	default "google/zork"
 
 config VARIANT_DIR
-	string
 	default "ezkinil" if BOARD_GOOGLE_EZKINIL
 	default "morphius" if BOARD_GOOGLE_MORPHIUS
 	default "trembyle" if BOARD_GOOGLE_TREMBYLE
diff --git a/src/mainboard/hp/snb_ivb_laptops/Kconfig b/src/mainboard/hp/snb_ivb_laptops/Kconfig
index 583fd4b..7a49bfd 100644
--- a/src/mainboard/hp/snb_ivb_laptops/Kconfig
+++ b/src/mainboard/hp/snb_ivb_laptops/Kconfig
@@ -20,7 +20,6 @@
 	default "hp/snb_ivb_laptops"
 
 config VARIANT_DIR
-	string
 	default "2560p"          if BOARD_HP_2560P
 	default "2570p"          if BOARD_HP_2570P
 	default "2760p"          if BOARD_HP_2760P
diff --git a/src/mainboard/intel/adlrvp/Kconfig b/src/mainboard/intel/adlrvp/Kconfig
index 608b8da..f622921 100644
--- a/src/mainboard/intel/adlrvp/Kconfig
+++ b/src/mainboard/intel/adlrvp/Kconfig
@@ -35,7 +35,6 @@
 	default "intel/adlrvp"
 
 config VARIANT_DIR
-	string
 	default "adlrvp_p" if BOARD_INTEL_ADLRVP_P
 	default "adlrvp_p_ext_ec" if BOARD_INTEL_ADLRVP_P_EXT_EC
 	default "adlrvp_m" if BOARD_INTEL_ADLRVP_M
diff --git a/src/mainboard/intel/coffeelake_rvp/Kconfig b/src/mainboard/intel/coffeelake_rvp/Kconfig
index f0c7f90..74111b5 100644
--- a/src/mainboard/intel/coffeelake_rvp/Kconfig
+++ b/src/mainboard/intel/coffeelake_rvp/Kconfig
@@ -23,7 +23,6 @@
 	default "intel/coffeelake_rvp"
 
 config VARIANT_DIR
-	string
 	default "cfl_u" if BOARD_INTEL_COFFEELAKE_RVPU
 	default "cfl_h" if BOARD_INTEL_COFFEELAKE_RVP11
 	default "whl_u" if BOARD_INTEL_WHISKEYLAKE_RVP
diff --git a/src/mainboard/intel/elkhartlake_crb/Kconfig b/src/mainboard/intel/elkhartlake_crb/Kconfig
index 3fb9954..0f880b5 100644
--- a/src/mainboard/intel/elkhartlake_crb/Kconfig
+++ b/src/mainboard/intel/elkhartlake_crb/Kconfig
@@ -18,7 +18,6 @@
 	default "intel/elkhartlake_crb"
 
 config VARIANT_DIR
-	string
 	default "ehlcrb" if BOARD_INTEL_ELKHARTLAKE_CRB
 
 config MAINBOARD_PART_NUMBER
diff --git a/src/mainboard/intel/glkrvp/Kconfig b/src/mainboard/intel/glkrvp/Kconfig
index 2d80b80..b5e61d9 100644
--- a/src/mainboard/intel/glkrvp/Kconfig
+++ b/src/mainboard/intel/glkrvp/Kconfig
@@ -49,7 +49,6 @@
 	default "intel/glkrvp"
 
 config VARIANT_DIR
-	string
 	default "glkrvp" if BOARD_INTEL_GLKRVP
 
 config DEVICETREE
diff --git a/src/mainboard/intel/icelake_rvp/Kconfig b/src/mainboard/intel/icelake_rvp/Kconfig
index b5088c3..4578afc1d 100644
--- a/src/mainboard/intel/icelake_rvp/Kconfig
+++ b/src/mainboard/intel/icelake_rvp/Kconfig
@@ -22,7 +22,6 @@
 	default "intel/icelake_rvp"
 
 config VARIANT_DIR
-	string
 	default "icl_u" if BOARD_INTEL_ICELAKE_RVPU
 	default "icl_y" if BOARD_INTEL_ICELAKE_RVPY
 
diff --git a/src/mainboard/intel/jasperlake_rvp/Kconfig b/src/mainboard/intel/jasperlake_rvp/Kconfig
index 88328d5..df5204f 100644
--- a/src/mainboard/intel/jasperlake_rvp/Kconfig
+++ b/src/mainboard/intel/jasperlake_rvp/Kconfig
@@ -25,7 +25,6 @@
 	default "intel/jasperlake_rvp"
 
 config VARIANT_DIR
-	string
 	default "jslrvp" if BOARD_INTEL_JASPERLAKE_RVP || BOARD_INTEL_JASPERLAKE_RVP_EXT_EC
 
 config MAINBOARD_PART_NUMBER
diff --git a/src/mainboard/intel/kblrvp/Kconfig b/src/mainboard/intel/kblrvp/Kconfig
index 5a4598b..2a0c135 100644
--- a/src/mainboard/intel/kblrvp/Kconfig
+++ b/src/mainboard/intel/kblrvp/Kconfig
@@ -28,7 +28,6 @@
 	default "intel/kblrvp"
 
 config VARIANT_DIR
-	string
 	default "rvp3" if BOARD_INTEL_KBLRVP3
 	default "rvp7" if BOARD_INTEL_KBLRVP7
 	default "rvp8" if BOARD_INTEL_KBLRVP8
diff --git a/src/mainboard/intel/tglrvp/Kconfig b/src/mainboard/intel/tglrvp/Kconfig
index 4f4cf12..c745b57 100644
--- a/src/mainboard/intel/tglrvp/Kconfig
+++ b/src/mainboard/intel/tglrvp/Kconfig
@@ -36,7 +36,6 @@
 	default "intel/tglrvp"
 
 config VARIANT_DIR
-	string
 	default "tglrvp_up3" if BOARD_INTEL_TGLRVP_UP3
 	default "tglrvp_up4" if BOARD_INTEL_TGLRVP_UP4
 
diff --git a/src/mainboard/kontron/bsl6/Kconfig b/src/mainboard/kontron/bsl6/Kconfig
index d79f374..0c3282a 100644
--- a/src/mainboard/kontron/bsl6/Kconfig
+++ b/src/mainboard/kontron/bsl6/Kconfig
@@ -40,7 +40,6 @@
 	default "Boxer26" if BOARD_SIEMENS_BOXER26
 
 config VARIANT_DIR
-	string
 	default "bsl6" if BOARD_KONTRON_BSL6
 	default "boxer26" if BOARD_SIEMENS_BOXER26
 
diff --git a/src/mainboard/kontron/mal10/Kconfig b/src/mainboard/kontron/mal10/Kconfig
index 631dd76..021e171 100644
--- a/src/mainboard/kontron/mal10/Kconfig
+++ b/src/mainboard/kontron/mal10/Kconfig
@@ -35,7 +35,6 @@
 endchoice
 
 config VARIANT_DIR
-	string
 	default "mal10"
 
 config CARRIER_DIR
diff --git a/src/mainboard/lenovo/t400/Kconfig b/src/mainboard/lenovo/t400/Kconfig
index 5e17eb5..74977eb 100644
--- a/src/mainboard/lenovo/t400/Kconfig
+++ b/src/mainboard/lenovo/t400/Kconfig
@@ -49,7 +49,6 @@
 	default "lenovo/t400"
 
 config VARIANT_DIR
-	string
 	default "t400" if BOARD_LENOVO_T400 || BOARD_LENOVO_T500 \
 		|| BOARD_LENOVO_R400 || BOARD_LENOVO_W500
 	default "r500" if BOARD_LENOVO_R500
diff --git a/src/mainboard/lenovo/t430s/Kconfig b/src/mainboard/lenovo/t430s/Kconfig
index 8881685..710dda2 100644
--- a/src/mainboard/lenovo/t430s/Kconfig
+++ b/src/mainboard/lenovo/t430s/Kconfig
@@ -51,7 +51,6 @@
 	default "lenovo/t430s"
 
 config VARIANT_DIR
-	string
 	default "t430s" if BOARD_LENOVO_T430S
 	default "t431s" if BOARD_LENOVO_T431S
 
diff --git a/src/mainboard/lenovo/t520/Kconfig b/src/mainboard/lenovo/t520/Kconfig
index e8f1df7..5e12056 100644
--- a/src/mainboard/lenovo/t520/Kconfig
+++ b/src/mainboard/lenovo/t520/Kconfig
@@ -43,7 +43,6 @@
 	default 0x2a
 
 config VARIANT_DIR
-	string
 	default "t520" if BOARD_LENOVO_T520
 	default "w520" if BOARD_LENOVO_W520
 
diff --git a/src/mainboard/lenovo/t530/Kconfig b/src/mainboard/lenovo/t530/Kconfig
index eb301db..c2d649c 100644
--- a/src/mainboard/lenovo/t530/Kconfig
+++ b/src/mainboard/lenovo/t530/Kconfig
@@ -47,7 +47,6 @@
 	default "src/mainboard/\$(CONFIG_MAINBOARD_DIR)/vboot-rwab.fmd" if VBOOT
 
 config VARIANT_DIR
-	string
 	default "t530" if BOARD_LENOVO_T530
 	default "w530" if BOARD_LENOVO_W530
 
diff --git a/src/mainboard/lenovo/t60/Kconfig b/src/mainboard/lenovo/t60/Kconfig
index 80e9c0e..c49cd0a 100644
--- a/src/mainboard/lenovo/t60/Kconfig
+++ b/src/mainboard/lenovo/t60/Kconfig
@@ -27,7 +27,6 @@
 	default "lenovo/t60"
 
 config VARIANT_DIR
-	string
 	default "t60" if BOARD_LENOVO_T60 || BOARD_LENOVO_R60
 	default "z61t" if BOARD_LENOVO_Z61T
 
diff --git a/src/mainboard/lenovo/x200/Kconfig b/src/mainboard/lenovo/x200/Kconfig
index c8783c1..b4d677a 100644
--- a/src/mainboard/lenovo/x200/Kconfig
+++ b/src/mainboard/lenovo/x200/Kconfig
@@ -45,7 +45,6 @@
 	default "lenovo/x200"
 
 config VARIANT_DIR
-	string
 	default "x200" if BOARD_LENOVO_X200
 	default "x301" if BOARD_LENOVO_X301
 
diff --git a/src/mainboard/lenovo/x220/Kconfig b/src/mainboard/lenovo/x220/Kconfig
index f4065d0..8530e49 100644
--- a/src/mainboard/lenovo/x220/Kconfig
+++ b/src/mainboard/lenovo/x220/Kconfig
@@ -45,7 +45,6 @@
 	default "lenovo/x220"
 
 config VARIANT_DIR
-	string
 	default "x220" if BOARD_LENOVO_X220 || BOARD_LENOVO_X220I
 	default "x1" if BOARD_LENOVO_X1
 
diff --git a/src/mainboard/lenovo/x230/Kconfig b/src/mainboard/lenovo/x230/Kconfig
index cc9d708..61144b8 100644
--- a/src/mainboard/lenovo/x230/Kconfig
+++ b/src/mainboard/lenovo/x230/Kconfig
@@ -51,7 +51,6 @@
 	default "lenovo/x230"
 
 config VARIANT_DIR
-	string
 	default "x230" if BOARD_LENOVO_X230 || BOARD_LENOVO_X230T
 	default "x230s" if BOARD_LENOVO_X230S
 
diff --git a/src/mainboard/lippert/frontrunner-af/Kconfig b/src/mainboard/lippert/frontrunner-af/Kconfig
index 7b34e64..e7472b1 100644
--- a/src/mainboard/lippert/frontrunner-af/Kconfig
+++ b/src/mainboard/lippert/frontrunner-af/Kconfig
@@ -24,7 +24,6 @@
 	default "lippert/frontrunner-af"
 
 config VARIANT_DIR
-	string
 	default "frontrunner-af" if BOARD_LIPPERT_FRONTRUNNER_AF
 	default "toucan-af"      if BOARD_LIPPERT_TOUCAN_AF
 
diff --git a/src/mainboard/pcengines/apu2/Kconfig b/src/mainboard/pcengines/apu2/Kconfig
index 6a65e5e..b4e1e9e 100644
--- a/src/mainboard/pcengines/apu2/Kconfig
+++ b/src/mainboard/pcengines/apu2/Kconfig
@@ -25,7 +25,6 @@
 	default "pcengines/apu2"
 
 config VARIANT_DIR
-	string
 	default "apu2" if BOARD_PCENGINES_APU2
 	default "apu3" if BOARD_PCENGINES_APU3
 	default "apu4" if BOARD_PCENGINES_APU4
diff --git a/src/mainboard/prodrive/hermes/Kconfig b/src/mainboard/prodrive/hermes/Kconfig
index 55fc780..bdb8e49 100644
--- a/src/mainboard/prodrive/hermes/Kconfig
+++ b/src/mainboard/prodrive/hermes/Kconfig
@@ -45,7 +45,6 @@
 	default n
 
 config VARIANT_DIR
-	string
 	default "baseboard"	if BOARD_PRODRIVE_HERMES_BASEBOARD
 
 config MAX_CPUS
diff --git a/src/mainboard/protectli/vault_bsw/Kconfig b/src/mainboard/protectli/vault_bsw/Kconfig
index f328d3d..23d1bfa 100644
--- a/src/mainboard/protectli/vault_bsw/Kconfig
+++ b/src/mainboard/protectli/vault_bsw/Kconfig
@@ -17,7 +17,6 @@
 	default "protectli/vault_bsw"
 
 config VARIANT_DIR
-	string
 	default "fw2b" if BOARD_PROTECTLI_FW2B
 	default "fw4b" if BOARD_PROTECTLI_FW4B
 
diff --git a/src/mainboard/purism/librem_bdw/Kconfig b/src/mainboard/purism/librem_bdw/Kconfig
index a5898cb..dfd1fe1 100644
--- a/src/mainboard/purism/librem_bdw/Kconfig
+++ b/src/mainboard/purism/librem_bdw/Kconfig
@@ -13,7 +13,6 @@
 if BOARD_PURISM_BASEBOARD_LIBREM_BDW
 
 config VARIANT_DIR
-	string
 	default "librem13v1" if BOARD_PURISM_LIBREM13_V1
 	default "librem15v2" if BOARD_PURISM_LIBREM15_V2
 
diff --git a/src/mainboard/purism/librem_cnl/Kconfig b/src/mainboard/purism/librem_cnl/Kconfig
index c87d763..2c960fd 100644
--- a/src/mainboard/purism/librem_cnl/Kconfig
+++ b/src/mainboard/purism/librem_cnl/Kconfig
@@ -29,7 +29,6 @@
 	default "Librem 14" if BOARD_PURISM_LIBREM_14
 
 config VARIANT_DIR
-	string
 	default "librem_mini" if BOARD_PURISM_LIBREM_MINI || BOARD_PURISM_LIBREM_MINI_V2
 	default "librem_14" if BOARD_PURISM_LIBREM_14
 
diff --git a/src/mainboard/purism/librem_skl/Kconfig b/src/mainboard/purism/librem_skl/Kconfig
index 191ca6e..35bd6f8 100644
--- a/src/mainboard/purism/librem_skl/Kconfig
+++ b/src/mainboard/purism/librem_skl/Kconfig
@@ -23,7 +23,6 @@
 	default 18
 
 config VARIANT_DIR
-	string
 	default "librem13" if BOARD_PURISM_LIBREM13_V2 || BOARD_PURISM_LIBREM13_V4
 	default "librem15" if BOARD_PURISM_LIBREM15_V3 || BOARD_PURISM_LIBREM15_V4
 
diff --git a/src/mainboard/roda/rv11/Kconfig b/src/mainboard/roda/rv11/Kconfig
index dd4b2a0..0a6b0cb 100644
--- a/src/mainboard/roda/rv11/Kconfig
+++ b/src/mainboard/roda/rv11/Kconfig
@@ -19,7 +19,6 @@
 	default "roda/rv11"
 
 config VARIANT_DIR
-	string
 	default "rv11" if BOARD_RODA_RV11
 	default "rw11" if BOARD_RODA_RW11
 
diff --git a/src/mainboard/siemens/chili/Kconfig b/src/mainboard/siemens/chili/Kconfig
index e8c74f1..470edf2 100644
--- a/src/mainboard/siemens/chili/Kconfig
+++ b/src/mainboard/siemens/chili/Kconfig
@@ -45,7 +45,6 @@
 	default "Chili" if BOARD_SIEMENS_CHILI_CHILI
 
 config VARIANT_DIR
-	string
 	default "base" if BOARD_SIEMENS_CHILI_BASE
 	default "chili" if BOARD_SIEMENS_CHILI_CHILI
 
diff --git a/src/mainboard/siemens/mc_apl1/Kconfig b/src/mainboard/siemens/mc_apl1/Kconfig
index 9a41274..f2f7e0e 100644
--- a/src/mainboard/siemens/mc_apl1/Kconfig
+++ b/src/mainboard/siemens/mc_apl1/Kconfig
@@ -15,7 +15,6 @@
 	default "siemens/mc_apl1"
 
 config VARIANT_DIR
-	string
 	default "mc_apl1" if BOARD_SIEMENS_MC_APL1
 	default "mc_apl2" if BOARD_SIEMENS_MC_APL2
 	default "mc_apl3" if BOARD_SIEMENS_MC_APL3
diff --git a/src/mainboard/siemens/mc_ehl/Kconfig b/src/mainboard/siemens/mc_ehl/Kconfig
index 239c06e..fb8dc03 100644
--- a/src/mainboard/siemens/mc_ehl/Kconfig
+++ b/src/mainboard/siemens/mc_ehl/Kconfig
@@ -15,7 +15,6 @@
 	default "siemens/mc_ehl"
 
 config VARIANT_DIR
-	string
 	default "mc_ehl1" if BOARD_SIEMENS_MC_EHL1
 
 config MAINBOARD_PART_NUMBER
diff --git a/src/mainboard/supermicro/x11-lga1151-series/Kconfig b/src/mainboard/supermicro/x11-lga1151-series/Kconfig
index aa7965c..4fc0ff8 100644
--- a/src/mainboard/supermicro/x11-lga1151-series/Kconfig
+++ b/src/mainboard/supermicro/x11-lga1151-series/Kconfig
@@ -31,7 +31,6 @@
 	default "supermicro/x11-lga1151-series"
 
 config VARIANT_DIR
-	string
 	default "x11ssh-tf"	if BOARD_SUPERMICRO_X11SSH_TF
 	default "x11ssm-f"	if BOARD_SUPERMICRO_X11SSM_F
 	default "x11ssh-f"	if BOARD_SUPERMICRO_X11SSH_F
diff --git a/src/mainboard/system76/whl-u/Kconfig b/src/mainboard/system76/whl-u/Kconfig
index 2493d74..1b8130a 100644
--- a/src/mainboard/system76/whl-u/Kconfig
+++ b/src/mainboard/system76/whl-u/Kconfig
@@ -25,7 +25,6 @@
 	default "system76/whl-u"
 
 config VARIANT_DIR
-	string
 	default "galp3-c" if BOARD_SYSTEM76_GALP3_C
 	default "darp5" if BOARD_SYSTEM76_DARP5