Input: goodix - add device tree support

This change adds device tree support and binding information for Goodix
GT9xx series touchscreen controller.  It also adds support for 5-finger
chips, like GT911 and GT912, which can be found on ARM tablets, such as
Wexler TAB7200 and MSI Primo73.

Datasheets can be found here:
https://drive.google.com/folderview?id=0BxCVOQS3ZymGfmJyY2RKbE5XbVlKNlktVTlwV0lxNEdxd2dzeWZER094cmJPVnMxN1F0Yzg&usp=sharing



Signed-off-by: Aleksei Mamlin <mamlinav@gmail.com>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>