Adds support for the EMR digitizer on the Cintiq 24HD touch. The
EMR digitizer should work identically to that found on the Cintiq
24HD. The touch digitizer is a separate USB device similar to how
we split apart some other devices.
Signed-off-by: NJason Gerecke <killertofu@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>