device: Add new Kconfig VGA_ROM_RUN_DEFAULT for mainboard user

Platform can now select VGA_ROM_RUN_DEFAULT Kconfig to perform graphics
initialization for PCI-E based discrete card through VGA OpRom
(SoC or Mainboard user can't select VGA_ROM_RUN directly because
it's part of choice option).

(Note: Some payloads, like SeaBIOS, are also able to run Option ROMs,
so coreboot does not need to enable VGA_ROM_RUN Kconfig)

For payload like depthcharge, create VGA_ROM_RUN_DEFAULT Kconfig
for mainboard to select design with DGPU where OpROM is embedded
inside the DGPU card.

Allow auto selection of VGA_ROM_RUN_DEFAULT from VGA_BIOS Kconfig.

Also NO_GFX_INIT Kconfig to avoid running VGA_ROM_RUN
by default in case SeaBIOS is used.

TEST=Able to get Pre-OS splash screen with AMD Radeon RX 5700 PCI-E
DGPU when mainboard user selects VGA_ROM_RUN_DEFAULT.

Change-Id: Iecb2fcdb105af449bc20ad727759cdef17d5e376
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49016
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/device/Kconfig b/src/device/Kconfig
index a472a6a..bb4e913 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -46,6 +46,12 @@
 	  Selected by mainboards / chipsets whose graphics driver can't or
 	  shouldn't be disabled.
 
+config VGA_ROM_RUN_DEFAULT
+	def_bool n
+	help
+	  Selected by mainboards whose graphics initialization depends on VGA OpROM.
+	  coreboot needs to load/execute legacy VGA OpROM in order to initialize GFX.
+
 config MAINBOARD_HAS_LIBGFXINIT
 	def_bool n
 	help
@@ -54,8 +60,8 @@
 
 choice
 	prompt "Graphics initialization"
-	default NO_GFX_INIT if VGA_BIOS && PAYLOAD_SEABIOS
-	default VGA_ROM_RUN if VGA_BIOS
+	default NO_GFX_INIT if VGA_ROM_RUN_DEFAULT && PAYLOAD_SEABIOS
+	default VGA_ROM_RUN if VGA_ROM_RUN_DEFAULT
 	default MAINBOARD_DO_NATIVE_VGA_INIT
 	default MAINBOARD_USE_LIBGFXINIT
 	default RUN_FSP_GOP if INTEL_GMA_HAVE_VBT
@@ -690,6 +696,7 @@
 config VGA_BIOS
 	bool "Add a VGA BIOS image"
 	depends on ARCH_X86
+	select VGA_ROM_RUN_DEFAULT
 	help
 	  Select this option if you have a VGA BIOS image that you would
 	  like to add to your ROM.