usb/uas: move UAS structs / defines into a header file

usb/uas: move UAS structs / defines into a header file

BugLink: http://bugs.launchpad.net/bugs/901215

The protocol specific structures and defines which are used by UAS are
moved into a header files by this patch so it can be accessed by the UAS
gadget as well.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
(cherry picked from commit 348748b0e8cccc675e2f3a1456460ffcd540e1a1)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Herton Krzesinski <herton.krzesinski@canonical.com>