Change in coreboot[master]: {mb, soc}: Move mrc_cache invalidating logic into `memory` common code

[Subrata Banik (Code Review)]

Attention is currently required from: Nick Vaccaro, Eric Lai, Patrick Rudolph, Zhuohao Lee.
Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62738 )

Change subject: {mb, soc}: Move mrc_cache invalidating logic into `memory` common code
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Patch Set 4:

(1 comment)

Patchset:

PS4:
> Better to verify on Brask or SODIMM variant for SPD cache again.

Yes, I will wait for Zhuohao to verify.