USB hcd.c, non-HS periodic transfers

This patch adds a missing "break", which prevented low and full
speed periodic transfers from getting through the "hcd" framework
to the driver (OHCI, for now).  Sigh... :)

drivers/usb/hcd.c

@@ -1356,6 +1356,7 @@ static int hcd_submit_urb (struct urb *urb, int mem_flags)
 				// NOTE usb and ohci handle up to 2^15
 				temp = 1024;
 			}
+			break;
 		default:
 			return -EINVAL;
 		}