usb: composite: Return bcdUSB 0x0310 for Superspeed and higher

As per USB 3.1 Specification, Revision 1.0, Section 9.6 all new
devices running at SuperSpeed or higher speeds must report a
bcdUSB of 0x0310.

CRs-Fixed: 2032555
Change-Id: I53fd403b66b42f98ee263aaa9c4bcb60855eb799
Signed-off-by: Devdutt Patnaik <dpatnaik@codeaurora.org>