powerpc/pci: Clean up direct access to sysdata by 52xx platforms

We shouldn't directly access sysdata to get the pci_controller.  Instead
use pci_bus_to_host() for this purpose.  In the future we might have
sysdata be a device_node to match ppc64 and unify the code between ppc32
& ppc64.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/52xx/efika.c

@@ -34,7 +34,7 @@
 static int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
 			    int len, u32 * val)
 {
-	struct pci_controller *hose = bus->sysdata;
+	struct pci_controller *hose = pci_bus_to_host(bus);
 	unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)
 	    | (((bus->number - hose->first_busno) & 0xff) << 16)
 	    | (hose->global_number << 24);
@@ -49,7 +49,7 @@ static int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
 static int rtas_write_config(struct pci_bus *bus, unsigned int devfn,
 			     int offset, int len, u32 val)
 {
-	struct pci_controller *hose = bus->sysdata;
+	struct pci_controller *hose = pci_bus_to_host(bus);
 	unsigned long addr = (offset & 0xff) | ((devfn & 0xff) << 8)
 	    | (((bus->number - hose->first_busno) & 0xff) << 16)
 	    | (hose->global_number << 24);