mb/google/skyrim: Add support for and select USE_SELECTIVE_GOP_INIT

Add a FMAP region to support caching GOP-driver-modified VBIOS tables.
Select SOC_AMD_GFX_CACHE_VBIOS_IN_FMAP if CHROMEOS && RUN_FSP_GOP.
Default USE_SELECTIVE_GOP_INIT to y if CHROMEOS && RUN_FSP_GOP.

BUG=b:255812886
TEST=build/boot skyrim, verify cached VBIOS data differs from VBIOS
in CBFS, cached VBIOS data is used when not booting in recovery
or developer modes.

Change-Id: I5857fa4a15250bf6478bffa96b16200e318492b1
Signed-off-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70900
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/mainboard/google/skyrim/Kconfig

@@ -43,6 +43,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select SOC_AMD_MENDOCINO
 	select SOC_AMD_COMMON_BLOCK_I2C3_TPM_SHARED_WITH_PSP
 	select SOC_AMD_COMMON_BLOCK_USE_ESPI
+	select SOC_AMD_GFX_CACHE_VBIOS_IN_FMAP if CHROMEOS && RUN_FSP_GOP
 	select SYSTEM_TYPE_LAPTOP
 	select TPM_GOOGLE_TI50
 	select PCIEXP_ASPM
@@ -114,6 +115,9 @@ config VARIANT_DIR
 	default "crystaldrift" if BOARD_GOOGLE_CRYSTALDRIFT
 	default "markarth" if BOARD_GOOGLE_MARKARTH
 
+config USE_SELECTIVE_GOP_INIT
+	default y if CHROMEOS && RUN_FSP_GOP
+
 config VBOOT
 	select EC_GOOGLE_CHROMEEC_SWITCHES
 	select VBOOT_LID_SWITCH

src/mainboard/google/skyrim/chromeos.fmd

@@ -21,6 +21,7 @@ FLASH@0xFF000000 16M {
 		RW_VPD(PRESERVE) 8K
 		RW_NVRAM(PRESERVE) 20K
 		SMMSTORE(PRESERVE)@0x630000 64K
+		RW_VBIOS_CACHE 64K
 		RW_LEGACY(CBFS)
 		WP_RO@8M 8M {
 			RO_VPD(PRESERVE) 16K