mb/google/reef: Fix WiFi SAR options

SAR-related Kconfigs are only used by ChromeOS, and should be guarded
properly as such (as most other boards do).

TEST=build reef w/o CONFIG_CHROMEOS, verify SAR-related Kconfigs not
selected.

Change-Id: I4fe3092e620bcbc33b0411ea69e55154fc118aa4
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68457
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/reef/Kconfig b/src/mainboard/google/reef/Kconfig
index 47d1114..fb02631 100644
--- a/src/mainboard/google/reef/Kconfig
+++ b/src/mainboard/google/reef/Kconfig
@@ -5,7 +5,6 @@
 	select DRIVERS_I2C_DA7219
 	select DRIVERS_I2C_GENERIC
 	select DRIVERS_I2C_HID
-	select DSAR_ENABLE
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_BOARDID
 	select EC_GOOGLE_CHROMEEC_LPC
@@ -17,11 +16,9 @@
 	select INTEL_LPSS_UART_FOR_CONSOLE
 	select MAINBOARD_HAS_CHROMEOS
 	select MAINBOARD_HAS_TPM2
-	select SAR_ENABLE
 	select SOC_INTEL_APOLLOLAKE
 	select SYSTEM_TYPE_LAPTOP
 	select TPM_GOOGLE_CR50
-	select USE_SAR
 
 config BOARD_GOOGLE_REEF
 	select BOARD_GOOGLE_BASEBOARD_REEF
@@ -40,6 +37,14 @@
 
 if BOARD_GOOGLE_BASEBOARD_REEF
 
+config CHROMEOS_WIFI_SAR
+	bool "Enable SAR options for ChromeOS build"
+	depends on CHROMEOS
+	default y if CHROMEOS
+	select DSAR_ENABLE
+	select SAR_ENABLE
+	select USE_SAR
+
 config DRIVER_TPM_I2C_BUS
 	hex
 	default 0x2