Change in coreboot[master]: soc/amd/common: Update SPI based on Kconfig & EFS instead of devtree

[Martin Roth (Code Review)]

Attention is currently required from: Jason Glenesk, Raul Rangel, Furquan Shaikh, Marshall Dawson, Karthik Ramasubramanian.
Martin Roth has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56959 )

Change subject: soc/amd/common: Update SPI based on Kconfig & EFS instead of devtree
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Patch Set 2:

(1 comment)

File src/soc/amd/common/block/psp/psp_efs.c:

https://review.coreboot.org/c/coreboot/+/56959/comment/e56038f9_89df1918 
PS2, Line 9: bool efs_is_valid(void)
> Nit: Should it be static? Seems not used outside this file in this CL.

Sure, I can update that in a follow-up.