Input: synaptics-rmi4 - add support for F3A

RMI4 F3A supports the touchpad GPIO function, it's designed to
support more GPIOs and used on newer touchpads. This patch adds
support of the touchpad buttons.

Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
Link: https://lore.kernel.org/r/20200930094147.635556-3-vincent.huang@tw.synaptics.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>