PCI: Add pci_unmap_iospace() to unmap I/O resources

Add pci_unmap_iospace() to undo what pci_remap_iospace() did.

This is needed to support hotplug removal of host bridges that use
pci_remap_iospace().

[bhelgaas: changelog]
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b67e4df..12349de 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1167,6 +1167,7 @@
 unsigned long pci_address_to_pio(phys_addr_t addr);
 phys_addr_t pci_pio_to_address(unsigned long pio);
 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
+void pci_unmap_iospace(struct resource *res);
 
 static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
 {