[M] Change in coreboot[master]: mb/google/rex: Add initial fw config

[Subrata Banik (Code Review)]

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

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/68220 )

Change subject: mb/google/rex: Add initial fw config
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Patch Set 4:

(1 comment)

File src/mainboard/google/rex/variants/rex0/overridetree.cb:

https://review.coreboot.org/c/coreboot/+/68220/comment/7420e556_94574b6f 
PS3, Line 156: 	probe DB_USB USB3
             : 							probe DB_USB USB4
> It will remove unnecessary ACPI code when USB DB is not present on a SKU. Is there any down side of it?

i assume those USB DBs are fixed and not configurable so that someone can build a board without those DBs attached.

hence, IMO, these are fixed configuration.