x86/PCI: MMCONFIG: add virtual address to struct pci_mmcfg_region

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: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index a6d42c1..7aa2ed8 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -124,6 +124,7 @@
 struct pci_mmcfg_region {
 	struct resource res;
 	u64 address;
+	char __iomem *virt;
 	u16 segment;
 	u8 start_bus;
 	u8 end_bus;