This is a follow-on to 'vPCI: avoid bogus "overlap in extended cap list"
warnings', addressing further issues noted there.

v3: Three new patches and some other re-work. See individual patches.

1: PCI: handle PCI->PCIe bridges as well in free_pdev()
2: PCI: determine whether a device has extended config space
3: PCI: don't look for ext-caps when there's no extended cfg space
4: vPCI/DomU: really no ext-caps without extended config space
5: x86/PCI: avoid re-evaluation of extended config space accessibility
6: vPCI: re-init extended-capability lists when MMCFG availability changed

Jan