Fix bug for io_bar size during pci scan

During the pci scan process, Some devices return bar_reponse with the
highest bytes 0, such as the pci bridge in uli1575 return bar_response
with 0xffffff, So the bar_size should be manually set under 64K.

Signed-off-by: Jason Jin <jason.jin@freescale.com>

drivers/pci_auto.c

@@ -102,7 +102,8 @@ void pciauto_setup_device(struct pci_controller *hose,
 
 		/* Check the BAR type and set our address mask */
 		if (bar_response & PCI_BASE_ADDRESS_SPACE) {
-			bar_size = ~(bar_response & PCI_BASE_ADDRESS_IO_MASK) + 1;
+			bar_size = ((~(bar_response & PCI_BASE_ADDRESS_IO_MASK))
+				   & 0xffff) + 1;
 			bar_res = io;
 
 			DEBUGF("PCI Autoconfig: BAR %d, I/O, size=0x%x, ", bar_nr, bar_size);