[M] Change in coreboot[master]: mb/google/rex: Add ISH support

[Bernardo Perez Priego (Code Review)]

Attention is currently required from: Tarun Tuli, Wonkyu Kim, Tanu Malhotra, Caveh Jalali, Li1 Feng, Kapil Porwal, Jay Patel, Boris Mittelberg, Gwendal Grignou.

Hello build bot (Jenkins), Wonkyu Kim, Tanu Malhotra, Li1 Feng, Jay Patel, Tanu Malhotra, Gwendal Grignou, Vijay P Hiremath, Tarun Tuli, Subrata Banik, Caveh Jalali, Kapil Porwal, Boris Mittelberg,

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

https://review.coreboot.org/c/coreboot/+/75039

to look at the new patch set (#5).

Change subject: mb/google/rex: Add ISH support
......................................................................

mb/google/rex: Add ISH support

This CL will enable ISH based on FW_CONFIG obtained form EC.

BUG=b:280329972
TEST= TBD

Signed-off-by: Bernardo Perez Priego 
Change-Id: Ibe0e1b8ce2c9b08ac6b1e6fef9bd19afc9b4f59f
---
M src/ec/google/chromeec/ec.h
M src/include/bootmode.h
M src/mainboard/google/rex/Kconfig
M src/mainboard/google/rex/chromeos.c
M src/mainboard/google/rex/chromeos.fmd
M src/mainboard/google/rex/variants/rex0/fw_config.c
M src/mainboard/google/rex/variants/rex0/overridetree.cb
M src/soc/intel/meteorlake/romstage/fsp_params.c
8 files changed, 78 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/39/75039/5