Elan touchpads on Asus ROG G752xx series laptops have 2 physical buttons.
Luckily we can query the touchpad to see if it is a clickpad variant and
adjust the behavior accordingly.
Signed-off-by: NKT Liao <kt.liao@emc.com.tw>
Tested-by: NMaxime Bellengé <maxime.bellenge@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>