Define pcibus_to_node() for IP27.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/mach-ip27/topology.h b/include/asm-mips/mach-ip27/topology.h
index a70a812..82141c7 100644
--- a/include/asm-mips/mach-ip27/topology.h
+++ b/include/asm-mips/mach-ip27/topology.h
@@ -9,6 +9,9 @@
 #define parent_node(node)	(node)
 #define node_to_cpumask(node)	(hub_data(node)->h_cpus)
 #define node_to_first_cpu(node)	(first_cpu(node_to_cpumask(node)))
+struct pci_bus;
+extern int pcibus_to_node(struct pci_bus *);
+
 #define pcibus_to_cpumask(bus)	(cpu_online_map)
 
 extern unsigned char __node_distances[MAX_COMPACT_NODES][MAX_COMPACT_NODES];