usb: add support for multiple usb controllers

Allows to initialize more than one USB controller at once.

v2: print message when controller stop fails

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/eth/usb_ether.c b/drivers/usb/eth/usb_ether.c
index 6cad6c8..f361e8b 100644
--- a/drivers/usb/eth/usb_ether.c
+++ b/drivers/usb/eth/usb_ether.c
@@ -123,7 +123,7 @@
 
 
 	if (mode == 1)
-		printf("       scanning bus for ethernet devices... ");
+		printf("       scanning usb for ethernet devices... ");
 
 	old_async = usb_disable_asynch(1); /* asynch transfer not allowed */