usb: gadget: ncm: Add super speed descriptors for NCM function

This change adds super speed descriptors which is required to
get NCM function to work with SSUSB mode. The burst capability
is not enabled for now.

This change also adds check against super speed descriptors
in usb_free_all_descriptors() API as all function driver may not
necessary to support super speed functionality.

CRs-Fixed: 804486
Change-Id: I6239ad9e64969afb4e9af87d76837b940c3d1348
Signed-off-by: Mayank Rana <mrana@codeaurora.org>