mb/google/rex: Use BOARD_GOOGLE_MODEL_REX instead variant name

Choose BOARD_GOOGLE_MODEL_REX while setting up the default config value
for variants created using google/rex model.

TEST=Able to build and boot google/rex.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I107f4e375b5c9e9c0fb80c4d396164c10c1fc1e7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76657
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>

0 files changed, 0 insertions, 0 deletions