[M] Change in coreboot[master]: drivers/intel/gma: Hook up libgfxinit in romstage

[Jérémy Compostella (Code Review)]

Attention is currently required from: Bora Guvendik, Zhixing Ma, Anil Kumar K, Hannah Williams, Cliff Huang, Tarun Tuli, Nico Huber, Michał Żygowski, Jérémy Compostella, Paul Menzel, Arthur Heymans.

Hello Bora Guvendik, build bot (Jenkins), Anil Kumar K, Cliff Huang, Paul Menzel, Angel Pons, Arthur Heymans, Zhixing Ma, Tarun Tuli, Nico Huber, Michał Żygowski, Nick Vaccaro, Boris Mittelberg,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/70276

to look at the new patch set (#20).

Change subject: drivers/intel/gma: Hook up libgfxinit in romstage
......................................................................

drivers/intel/gma: Hook up libgfxinit in romstage

A mainboard port needs to:

- select `CONFIG_MAINBOARD_HAS_EARLY_LIBGFXINIT'

- implement the Ada package `GMA.Mainboard' with a single function
  `ports' that returns a list of ports to be probed for displays.

- set the desired `GFX_GMA_DEFAULT_MMIO' IO memory address to use
  in romstage for the graphic device.

BUG=b:252792591
BRANCH=firmware-brya-14505.B
TEST=libgfxinit compiles in romstage.
     libgfxinit successfully executes in romstage and ramstage using
     the requested MMIO setting on skolas.

Change-Id: I3c2101de10dc5df54fe873e43bbe0f1c4dccff44
Signed-off-by: Jeremy Compostella 
---
M src/arch/x86/car.ld
M src/device/Kconfig
M src/drivers/intel/gma/Kconfig
M src/drivers/intel/gma/Makefile.inc
M src/soc/intel/common/block/graphics/graphics.c
5 files changed, 124 insertions(+), 11 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/76/70276/20