PCI: replace struct pci_bus secondary/subordinate with busn_res

Replace the struct pci_bus secondary/subordinate members with the
struct resource busn_res.  Later we'll build a resource tree of these
bus numbers.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/arch/microblaze/pci/pci-common.c b/arch/microblaze/pci/pci-common.c
index ed22bfc..9b32483 100644
--- a/arch/microblaze/pci/pci-common.c
+++ b/arch/microblaze/pci/pci-common.c
@@ -1506,10 +1506,10 @@
 		pci_free_resource_list(&resources);
 		return;
 	}
-	bus->secondary = hose->first_busno;
+	bus->busn_res.start = hose->first_busno;
 	hose->bus = bus;
 
-	hose->last_busno = bus->subordinate;
+	hose->last_busno = bus->busn_res.end;
 }
 
 static int __init pcibios_init(void)