atmel_usba_udc: Keep track of the device status

Keep track of the device status (as returned by the GET_STATUS
request) and allow it to be manipulated by set_selfpowered() as
well as SET_FEATURE/CLEAR_FEATURE (for remote wakeup)

Implement the wakeup() op, which refuses to do anything if the
DEVICE_REMOTE_WAKEUP feature wasn't set by the host.  Now this
driver passes USBCV (at least, with gadget zero).

Fix one more locking bug; lockdep is every developer's friend.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>