powerpc/pci: Clean up direct access to sysdata by CHRP 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/chrp/pci.c

@@ -34,7 +34,7 @@ int gg2_read_config(struct pci_bus *bus, unsigned int devfn, int off,
 			   int len, u32 *val)
 {
 	volatile void __iomem *cfg_data;
-	struct pci_controller *hose = bus->sysdata;
+	struct pci_controller *hose = pci_bus_to_host(bus);
 
 	if (bus->number > 7)
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -61,7 +61,7 @@ int gg2_write_config(struct pci_bus *bus, unsigned int devfn, int off,
 			    int len, u32 val)
 {
 	volatile void __iomem *cfg_data;
-	struct pci_controller *hose = bus->sysdata;
+	struct pci_controller *hose = pci_bus_to_host(bus);
 
 	if (bus->number > 7)
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -96,7 +96,7 @@ static struct pci_ops gg2_pci_ops =
 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);
@@ -111,7 +111,7 @@ int rtas_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
 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);