HID: wacom: Add tilt reporting for Intuos4 WL

Tile is reported to input subsystem as reported by the device without
any modifications. It means that tilt X/Y range is 0 to 127 and it's
not centered on zero.

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>