Change in coreboot[master]: guybrush: add RO_GSCVD area to FMAP

[Karthik Ramasubramanian (Code Review)]

Attention is currently required from: Hung-Te Lin, Raul Rangel, Vadim Bendebury, Furquan Shaikh, Mathew King, Paul Menzel, Julius Werner, Rob Barnes.
Karthik Ramasubramanian has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57864 )

Change subject: guybrush: add RO_GSCVD area to FMAP
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Patch Set 2: Code-Review+2

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/57864/comment/ce8df7cd_28a5c420 
PS2, Line 25: 
Cq-Depend: TBD

Reason: Since signed PSP verstage has a snapshot of different FMAP, it will fail to boot. This change is good to land upstream. For downstream, we have to sign the PSP verstage with the updated FMAP and land it along with the downstream CL.

Patchset:

PS2: 
Adding Raul/Rob for visibility.