[M] Change in coreboot[master]: rex: add variant gpio tables for variant creation

[Subrata Banik (Code Review)]

Attention is currently required from: YH Lin, Tarun Tuli, Kapil Porwal.

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74257 )

Change subject: rex: add variant gpio tables for variant creation
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Patch Set 1:

(1 comment)

Patchset:

PS1: 
The implementation is little different in Rex in terms GPIO (compared to the Brya)
where we allow each variant to have their own variant_gpio_table() for bootblock/romstage/ramstage without bothering about an override from the baseboard.
This would make things simple enough.

Please find more details here:

https://github.com/coreboot/coreboot/commit/7c5a9c7cb0cf6605435aa4c885c63727...