src/*/intel/: clarify Kconfig options regarding IFD

HAVE_INTEL_FIRMWARE is used to enable certain options that rely on a valid
Inter Flash Descriptor to exist. It does *not* identify platforms or boards
that are capable of running in descriptor mode if it's valid.
Refine the help text to make this clear.

Introduce a new option INTEL_DESCRIPTOR_MODE_CAPABLE that does simply
declare that IFD is supported by the platform. Select this value everywhere
instead of the HAVE_INTEL_FIRMWARE and default HAVE_INTEL_FIRMWARE to
y if INTEL_DESCRIPTOR_MODE_CAPABLE is selected.

Move the QEMU Q35 special case (deselection of HAVE_INTEL_FIRMWARE) to
the mainboard directory.

Change-Id: I4791fce03982bf0443bf0b8e26d9f4f06c6f2060
Signed-off-by: Stefan Tauner <stefan.tauner@gmx.at>
Reviewed-on: https://review.coreboot.org/28371
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index 3e84a50..4dcecf5 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -45,7 +45,7 @@
 	select COMMON_FADT
 	select FSP_PLATFORM_MEMORY_SETTINGS_VERSIONS
 	select GENERIC_GPIO_LIB
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_SMI_HANDLER
 	select MRC_SETTINGS_PROTECT
 	select MRC_SETTINGS_VARIABLE_DATA
diff --git a/src/soc/intel/baytrail/Kconfig b/src/soc/intel/baytrail/Kconfig
index b4dc823..7b87766 100644
--- a/src/soc/intel/baytrail/Kconfig
+++ b/src/soc/intel/baytrail/Kconfig
@@ -34,7 +34,7 @@
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select SOC_INTEL_COMMON
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_SPI_CONSOLE_SUPPORT
 	select INTEL_GMA_ACPI
 	select INTEL_GMA_SWSMISCI
diff --git a/src/soc/intel/braswell/Kconfig b/src/soc/intel/braswell/Kconfig
index 607d78c..2799e5b 100644
--- a/src/soc/intel/braswell/Kconfig
+++ b/src/soc/intel/braswell/Kconfig
@@ -42,7 +42,7 @@
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select USE_GENERIC_FSP_CAR_INC
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_SPI_CONSOLE_SUPPORT
 	select HAVE_FSP_GOP
 	select GENERIC_GPIO_LIB
diff --git a/src/soc/intel/broadwell/Kconfig b/src/soc/intel/broadwell/Kconfig
index 32148c4..ffd7c73 100644
--- a/src/soc/intel/broadwell/Kconfig
+++ b/src/soc/intel/broadwell/Kconfig
@@ -35,7 +35,7 @@
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select SOC_INTEL_COMMON
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select SOC_INTEL_COMMON_ACPI_WAKE_SOURCE
 	select HAVE_SPI_CONSOLE_SUPPORT
 	select CPU_INTEL_COMMON
diff --git a/src/soc/intel/cannonlake/Kconfig b/src/soc/intel/cannonlake/Kconfig
index 310ed24..3392728 100644
--- a/src/soc/intel/cannonlake/Kconfig
+++ b/src/soc/intel/cannonlake/Kconfig
@@ -36,7 +36,7 @@
 	select GENERIC_GPIO_LIB
 	select HAVE_FSP_GOP
 	select HAVE_HARD_RESET
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_MONOTONIC_TIMER
 	select HAVE_SMI_HANDLER
 	select IDT_IN_EVERY_STAGE
diff --git a/src/soc/intel/denverton_ns/Kconfig b/src/soc/intel/denverton_ns/Kconfig
index 6c366f1..4517065 100644
--- a/src/soc/intel/denverton_ns/Kconfig
+++ b/src/soc/intel/denverton_ns/Kconfig
@@ -43,6 +43,7 @@
 	select PARALLEL_MP
 	select PCR_COMMON_IOSF_1_0
 	select SMP
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select SOC_INTEL_COMMON_BLOCK
 	select SOC_INTEL_COMMON_BLOCK_CPU
 #	select SOC_INTEL_COMMON_BLOCK_SA
diff --git a/src/soc/intel/fsp_baytrail/Kconfig b/src/soc/intel/fsp_baytrail/Kconfig
index 68084bc..2019b6d 100644
--- a/src/soc/intel/fsp_baytrail/Kconfig
+++ b/src/soc/intel/fsp_baytrail/Kconfig
@@ -41,7 +41,7 @@
 	select TSC_SYNC_MFENCE
 	select UDELAY_TSC
 	select SUPPORT_CPU_UCODE_IN_CBFS
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_SPI_CONSOLE_SUPPORT
 
 	# Microcode header files are delivered in FSP package
diff --git a/src/soc/intel/fsp_broadwell_de/Kconfig b/src/soc/intel/fsp_broadwell_de/Kconfig
index 37876b5..5f09bdd 100644
--- a/src/soc/intel/fsp_broadwell_de/Kconfig
+++ b/src/soc/intel/fsp_broadwell_de/Kconfig
@@ -22,7 +22,7 @@
 	select SUPPORT_CPU_UCODE_IN_CBFS
 	# Microcode header files are delivered in FSP package
 	select USES_MICROCODE_HEADER_FILES if HAVE_FSP_BIN
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select SMM_TSEG
 	select HAVE_SMI_HANDLER
 	select TSC_MONOTONIC_TIMER
diff --git a/src/soc/intel/skylake/Kconfig b/src/soc/intel/skylake/Kconfig
index 9412b03..9a5aae4 100644
--- a/src/soc/intel/skylake/Kconfig
+++ b/src/soc/intel/skylake/Kconfig
@@ -32,7 +32,7 @@
 	select GENERIC_GPIO_LIB
 	select HAVE_FSP_GOP
 	select HAVE_HARD_RESET
-	select HAVE_INTEL_FIRMWARE
+	select INTEL_DESCRIPTOR_MODE_CAPABLE
 	select HAVE_MONOTONIC_TIMER
 	select HAVE_SMI_HANDLER
 	select INTEL_GMA_ACPI