The virtual address is only used for x86_64, but it's so much simpler
to manage it as part of the pci_mmcfg_region that I think it's worth
wasting a pointer per MMCONFIG region on x86_32.
Reviewed-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>