[POWERPC] Fix mpc834x USB-MPH configuration.

mpc834x USB-MPH configuration got broken by commit
6f442560021aecf08658e26ed9a37e6928ef0fa1. The selection bits in SICRL
should be cleared rather than set to configure the USB MUXes for the MPH.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/83xx/usb.c

@@ -76,14 +76,14 @@ int mpc834x_usb_cfg(void)
 			if (port0_is_dr)
 				printk(KERN_WARNING
 					"834x USB port0 can't be used by both DR and MPH!\n");
-			sicrl |= MPC834X_SICRL_USB0;
+			sicrl &= ~MPC834X_SICRL_USB0;
 		}
 		prop = of_get_property(np, "port1", NULL);
 		if (prop) {
 			if (port1_is_dr)
 				printk(KERN_WARNING
 					"834x USB port1 can't be used by both DR and MPH!\n");
-			sicrl |= MPC834X_SICRL_USB1;
+			sicrl &= ~MPC834X_SICRL_USB1;
 		}
 		of_node_put(np);
 	}