Change in coreboot[master]: soc/amd/stoneyridge/psp: fix check of MSR_PSP_ADDR contents

[Felix Held (Code Review)]

Attention is currently required from: Raul Rangel, Angel Pons.
Felix Held has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50150 )

Change subject: soc/amd/stoneyridge/psp: fix check of MSR_PSP_ADDR contents
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Patch Set 1:

(1 comment)

File src/soc/amd/stoneyridge/psp.c:

https://review.coreboot.org/c/coreboot/+/50150/comment/3691c3ea_3de6f8ea 
PS1, Line 48: 		if (!psp_mmio) {
> If in doubt, we could simply treat both all-zeroes and all-ones as invalid values.

the Stoneyridge datasheet says that it's all zeros if uninitialized. The datasheet for Picasso says the same and there I've verified it on hardware