[S] Change in coreboot[main]: mb/var/uldrenite: Configure descriptor for either MBVR or FIVR

[John Su (Code Review)]

Attention is currently required from: Ben Kao, Dinesh Gehlot, Dtrain Hsu, Eric Lai, Jamie Chen, Jayvik Desai, Kapil Porwal, Nick Vaccaro, Subrata Banik.

Hello Ben Kao, Dinesh Gehlot, Eric Lai, Jamie Chen, Jayvik Desai, Kapil Porwal, Nick Vaccaro, Subrata Banik,

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

https://review.coreboot.org/c/coreboot/+/87033?usp=email

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

Change subject: mb/var/uldrenite: Configure descriptor for either MBVR or FIVR
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mb/var/uldrenite: Configure descriptor for either MBVR or FIVR

According to the root cause analysis in b/404126972#comment22,
Right now, it is set to FIVR, , which leads to a system reboot issue
due to OVP being triggered (MBVR and FIVR existing simultaneously).

The current build's main source is MBVR, so we want to use fw_config
to dynamically adjust MFIT and MBVR with the current phase devices to
ensure consistency in client devices settings.

CONFIGURE_DESCRIPTOR is a temporary workaround for the current phase.
In the next phase, we will choose a specific setting for implementation.
If there are any concerns, we use the board ID to restrict it.

BUG=b:404126972
TEST=boot to ChromeOS

Change-Id: I337574c8c55889ceb49b9f33625feadb48bd8890
Signed-off-by: John Su 
---
M src/mainboard/google/brya/Kconfig
M src/mainboard/google/brya/variants/uldrenite/Makefile.mk
M src/mainboard/google/brya/variants/uldrenite/variant.c
M src/soc/intel/alderlake/bootblock/update_descriptor.c
4 files changed, 33 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/33/87033/5