[coreboot-gerrit] Change in coreboot[master]: soc/mediatek: Add PCIe support

[Jianjun Wang (Code Review)]

Attention is currently required from: Shelley Chen, Hung-Te Lin, Furquan Shaikh, Paul Menzel, Yu-Ping Wu.
Jianjun Wang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56791 )

Change subject: soc/mediatek: Add PCIe support
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Patch Set 4:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/56791/comment/c8036bf9_d95c129e 
PS3, Line 11:
> > MT8195 Register Map V0.3-2, Chapter 3.18 PCIe controller (Page 1250). […]

This file is created based on MT8195, but all these codes should be common in each platform with the same PCIe IP in the future.

Since this file is not platform related, I'm not sure if this is a good idea to add this comment in pcie.c like src/soc/mediatek/mt8186/pll.c does.