ssb: use pci_dev->revision

The bus scan code reads PCI revision ID from the PCI configuration register
while it's already stored by PCI subsystem in the 'revision' field of 'struct
pci_dev'...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/scan.c

@@ -310,8 +310,7 @@ int ssb_bus_scan(struct ssb_bus *bus,
 	} else {
 		if (bus->bustype == SSB_BUSTYPE_PCI) {
 			bus->chip_id = pcidev_to_chipid(bus->host_pci);
-			pci_read_config_byte(bus->host_pci, PCI_REVISION_ID,
-					     &bus->chip_rev);
+			bus->chip_rev = bus->host_pci->revision;
 			bus->chip_package = 0;
 		} else {
 			bus->chip_id = 0x4710;