usb: define USB_SPEED_SUPER_PLUS speed for SuperSpeedPlus USB3.1 devices

Add a new USB_SPEED_SUPER_PLUS device speed, and make sure usb core can
handle the new speed.
In most cases the behaviour is the same as with USB_SPEED_SUPER SuperSpeed
devices. In a few places we add a "Plus" string to inform the user of the
new speed.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/uapi/linux/usb/ch9.h b/include/uapi/linux/usb/ch9.h
index 4338eb7..779a62a 100644
--- a/include/uapi/linux/usb/ch9.h
+++ b/include/uapi/linux/usb/ch9.h
@@ -954,6 +954,7 @@
 	USB_SPEED_HIGH,				/* usb 2.0 */
 	USB_SPEED_WIRELESS,			/* wireless (usb 2.5) */
 	USB_SPEED_SUPER,			/* usb 3.0 */
+	USB_SPEED_SUPER_PLUS,			/* usb 3.1 */
 };