[M] Change in coreboot[main]: mb/asus/p8z77-v: Attempt to correctly route PCIe lanes

[Keith Hui (Code Review)]

Attention is currently required from: Angel Pons, Bill XIE, Nicholas Chin.

Keith Hui has posted comments on this change by Keith Hui. ( https://review.coreboot.org/c/coreboot/+/85413?usp=email )

Change subject: mb/asus/p8z77-v: Attempt to correctly route PCIe lanes
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Patch Set 4:

(1 comment)

Patchset:

PS4: 
Hi Bill, I added CB:86191 after this patch that updates the PCH interrupt mapping from the logs you sent me. I know this is yet another hail-mary because it doesn't affect the PCIe root ports. But do try it and watch for regressions.