[POWERPC] Use global_number in ppc32 pci_controller

Make the pci_controller struct use global_number for the PHB domain number
instead of index to match what ppc64 does and reuse its pci_domain_nr code.

Introduced a pci-common.c to handle shared code between ppc32 & ppc64.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/asm-powerpc/pci.h b/include/asm-powerpc/pci.h
index 93e3752..0cd3e77 100644
--- a/include/asm-powerpc/pci.h
+++ b/include/asm-powerpc/pci.h
@@ -107,8 +107,6 @@
 #define get_pci_dma_ops()	NULL
 #endif
 
-extern int pci_domain_nr(struct pci_bus *bus);
-
 /* Decide whether to display the domain number in /proc */
 extern int pci_proc_domain(struct pci_bus *bus);
 
@@ -130,9 +128,6 @@
  */
 #define pci_dac_dma_supported(pci_dev, mask)	(0)
 
-/* Return the index of the PCI controller for device PDEV. */
-#define pci_domain_nr(bus) ((struct pci_controller *)(bus)->sysdata)->index
-
 /* Set the name of the bus as it appears in /proc/bus/pci */
 static inline int pci_proc_domain(struct pci_bus *bus)
 {
@@ -141,6 +136,8 @@
 
 #endif /* CONFIG_PPC64 */
 
+extern int pci_domain_nr(struct pci_bus *bus);
+
 struct vm_area_struct;
 /* Map a range of PCI memory or I/O space for a device into user space */
 int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma,