[POWERPC] Add "parent" struct device for PCI host bridges

Add a "parent" struct device to our PCI host bridge data structure so that
PCI can be rooted off another device in sysfs.

Note that arch/ppc doesn't use it, only arch/powerpc, though it's available
for both 32 and 64 bits.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-ppc/pci-bridge.h b/include/asm-ppc/pci-bridge.h
index 9d52306..6c955d0 100644
--- a/include/asm-ppc/pci-bridge.h
+++ b/include/asm-ppc/pci-bridge.h
@@ -43,6 +43,7 @@
 	struct pci_controller *next;
         struct pci_bus *bus;
 	void *arch_data;
+	struct device *parent;
 
 	int first_busno;
 	int last_busno;