Input: appletouch - add support for Geyser 2

This patch adds support for the Geyser 2 touchpads used on post Oct 2005
Apple PowerBooks to the appletouch driver.

Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Rene Nussbaumer <linux-kernel@killerfox.forkbomb.ch>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>