mb/google/corsola: Add RO_GSCVD area to FMAP

This area is used for storing AP RO verification data.

BUG=b:229670703
TEST=emerge-corsola coreboot
TEST=cbfstool /build/corsola/firmware/kingler/coreboot.rom layout
BRANCH=none

Change-Id: Id0a3304920c80987319d8072b8e443c41c1f1c47
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63781
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

src/mainboard/google/corsola/chromeos.fmd

@@ -19,6 +19,7 @@ FLASH@0x0 8M {
 			GBB 0x2f00
 			RO_FRID 0x100
 		}
+		RO_GSCVD 8K
 		RO_VPD(PRESERVE) 32K  # At least 16K.
 	}
 	RW_SECTION_A 1500K {