quirks: Add quirks for Acer Switch Alpha 12

This is a 2-in-1 laptop with detachable keyboard. The AT keyboard
device is used for tablet-integrated keys (volume, leftmeta) and
should not get disabled with tablet-mode enabled.

The touchpad integrated in the detachable keyboard is already
handled through the "Acer Hawaii Keyboard" chicony rule.

Related: https://gitlab.freedesktop.org/libinput/libinput/issues/115



Signed-off-by: Carlos Garnacho <carlosg@gnome.org>