udev: Add hwdb file for setting pointingstick properties

udev: Add hwdb file for setting pointingstick properties

There is quite a wide spread in the delta events generated by pointingsticks,
some generate deltas of 1-2 under normal use, while others generate deltas
from 1-20.

This commit adds a hwdb file which allows specifying a per model
POINTINGSTICK_CONST_ACCEL value which can be used by the userspace input stack
to normalize the deltas so that all pointingsticks get the same feeling ootb.

The hwdb matching re-uses the existing 60-evdev.rules.