Input: wistron - add support for TravelMate 610

Add support for Acer TravelMate 610 to wistron_btns. All special keys
are detected, but the 2 leds are not handled (yet).

Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>