x86/PCI: set_pci_bus_resources_arch_default cleanups

Rename set_pci_bus_resources_arch_default to x86_pci_root_bus_res_quirks, move
the weak version from common.c to i386.c, and before calling, make sure it's a
root bus.

Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/pci/amd_bus.c b/arch/x86/pci/amd_bus.c
index 9bb0982..e121ee0 100644
--- a/arch/x86/pci/amd_bus.c
+++ b/arch/x86/pci/amd_bus.c
@@ -94,7 +94,7 @@
 static int pci_root_num;
 static struct pci_root_info pci_root_info[PCI_ROOT_NR];
 
-void set_pci_bus_resources_arch_default(struct pci_bus *b)
+void x86_pci_root_bus_res_quirks(struct pci_bus *b)
 {
 	int i;
 	int j;