Change in coreboot[master]: mb/google/rex: Add entry stubs of each stage

[Eric Lai (Code Review)]

Attention is currently required from: Tarun Tuli, Subrata Banik, Tim Wawrzynczak, Kapil Porwal.
Hello Tarun Tuli, Subrata Banik, Tim Wawrzynczak, Kapil Porwal,

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

https://review.coreboot.org/c/coreboot/+/64591

to look at the new patch set (#2).

Change subject: mb/google/rex: Add entry stubs of each stage
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mb/google/rex: Add entry stubs of each stage

Add entry point stubs of each stage for Brya. More functionalities will
be added later.

BUG=b:224325352
TEST=util/abuild/abuild -p none -t google/rex -a -c max

Signed-off-by: Eric Lai 
Change-Id: I2310e58ab92bdb0ce86a9f7284cc0b3e04a2889f
---
A src/mainboard/google/rex/Makefile.inc
A src/mainboard/google/rex/bootblock.c
A src/mainboard/google/rex/mainboard.c
A src/mainboard/google/rex/romstage.c
A src/mainboard/google/rex/variants/baseboard/include/baseboard/variants.h
A src/mainboard/google/rex/variants/baseboard/rex/include/baseboard/gpio.h
6 files changed, 64 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/91/64591/2