HID: multitouch: Add pointstick support for ALPS Touchpad

There's a new ALPS touchpad/pointstick combo device that requires
MT_CLS_WIN_8_DUAL to make its pointsitck work as a mouse.

The device can be found on HP ZBook 17 G5.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>