PCI: xgene: Add register offset to config space base address

In xgene_pcie_map_bus(), we neglected to add in the register offset when
calculating the config space address.  This means all config accesses
operated on the first four bytes of config space.

Add the register offset to the config space base address.

Also correct the xgene_pcie_map_bus() prototype to fix a compiler warning.

[bhelgaas: changelog]
Fixes: 350f8be ("PCI: xgene: Convert to use generic config accessors")
Posting: http://lkml.kernel.org/r/1424214840-26498-1-git-send-email-fkan@apm.com
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tanmay Inamdar <tinamdar@apm.com>
Acked-by: Rob Herring <robh@kernel.org>

drivers/pci/host/pci-xgene.c

@@ -127,7 +127,7 @@ static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
 	return false;
 }
 
-static int xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+static void __iomem *xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
 			      int offset)
 {
 	struct xgene_pcie_port *port = bus->sysdata;
@@ -137,7 +137,7 @@ static int xgene_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
 		return NULL;
 
 	xgene_pcie_set_rtdid_reg(bus, devfn);
-	return xgene_pcie_get_cfg_base(bus);
+	return xgene_pcie_get_cfg_base(bus) + offset;
 }
 
 static struct pci_ops xgene_pcie_ops = {