HID: Add transport-driver functions to the USB HID interface.

Add raw_request, set_raw_report and output_report transport-driver functions to
the USB HID driver.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Acked-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>