MIPS/PCI: Implement pcibios_get_phb_of_node

The of_node field of the device assigned to a
PCI bus is used during scanning of the PCI bus.
However on MIPS, the of_node field is assigned
only after the bus has been scanned.

Implement the architecture specific version of
'pcibios_get_phb_of_node'. Which ensures that the
PCI driver core will initialize the of_node field
before starting the scan.

Also remove the local assignment of bus->dev.of_node,
it is not needed after the patch.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/mips/pci/pci.c

@@ -115,7 +115,6 @@ static void pcibios_scanbus(struct pci_controller *hose)
 			pci_bus_assign_resources(bus);
 			pci_enable_bridges(bus);
 		}
-		bus->dev.of_node = hose->of_node;
 	}
 }
 
@@ -169,6 +168,13 @@ void pci_load_of_ranges(struct pci_controller *hose, struct device_node *node)
 		}
 	}
 }
+
+struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
+{
+	struct pci_controller *hose = bus->sysdata;
+
+	return of_node_get(hose->of_node);
+}
 #endif
 
 static DEFINE_MUTEX(pci_scan_mutex);