Patch enables SuperSpeed for NCM gadget.

Tested with USB3380 and measured TCP throughput with two Intel PCs:
  udc to host: 920 Mbit/s
  host to udc: 550 Mbit/s
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@haltian.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>