hid: egalax: Setup input device manually

The hid core does not yet handle input filtering. Take over the setup
of the input device, so that proper signal-to-noise ratios can be
used.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Stephane Chatty <chatty@enac.fr>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>