HID: wacom: Add fuzz factor to distance and tilt axes

The fuzz present on the distance and tilt axes is noticable when a puck is
present, and userspace (specifically libinput) would like the ability to
filter out the noise. To facilitate this, we assign a fuzz value of '1'
for the distance and tilt axes. This is large enough to cover most of the
natural variation in distance value as the puck is moved around, and
enough to cover the jitter in rotation (reported through tilt axes) when
the puck is left alone.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>