Tablet reports a distance of 0 right at highest point possible
to be in proximity and distance_max when touching tablet. Inverse
the distance since user land has no way of knowing ABS_DISTANCE
is not distance from tablet.
Signed-off-by: NChris Bagwell <chris@cnpbagwell.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>