Change in coreboot[master]: libpayload/pci: Split PCI interfaces as common and chip related

[Jianjun Wang (Code Review)]

Attention is currently required from: Hung-Te Lin, Furquan Shaikh.
Jianjun Wang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56789 )

Change subject: libpayload/pci: Split PCI interfaces as common and chip related
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Patch Set 11:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/56789/comment/f87d6a2b_a39a7c4f 
PS2, Line 7: Split PCI interfaces as common and chip related
> I haven't looked at the entire chain in detail yet, but I had provided some feedback on CB:53903 w. […]

Thanks for the suggestion, I add 'pci_map_bus()' for users to get the base address of config space in CL:56794.
Normally for embedded platform, the base address of PCIe hardware might be different, so I also provide a 'pci_update_hw_base()' function for users(e.g. depthcharge) to set its hardware base address, is that ok?