[POWERPC] Fix IO Window Updates on P2P bridges.

When update_bridge_base() updates the IO window on a PCI-to-PCI
bridge, it fails to zero the upper 16 bits of the base and limit
registers if the window size is less than 64K.  This fixes it.
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/pci_32.c

@@ -441,14 +441,14 @@ update_bridge_base(struct pci_bus *bus, int i)
 		end = res->end - off;
 		io_base_lo = (start >> 8) & PCI_IO_RANGE_MASK;
 		io_limit_lo = (end >> 8) & PCI_IO_RANGE_MASK;
-		if (end > 0xffff) {
+		if (end > 0xffff)
+			io_base_lo |= PCI_IO_RANGE_TYPE_32;
+		else
+			io_base_lo |= PCI_IO_RANGE_TYPE_16;
 		pci_write_config_word(dev, PCI_IO_BASE_UPPER16,
 				start >> 16);
 		pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16,
 				end >> 16);
-			io_base_lo |= PCI_IO_RANGE_TYPE_32;
-		} else
-			io_base_lo |= PCI_IO_RANGE_TYPE_16;
 		pci_write_config_byte(dev, PCI_IO_BASE, io_base_lo);
 		pci_write_config_byte(dev, PCI_IO_LIMIT, io_limit_lo);