Input: add driver for Neonode zForce based touchscreens

This adds a driver for touchscreens using the zforce infrared
technology from Neonode connected via i2c to the host system.

It supports multitouch with up to two fingers and tracking of the
contacts in hardware.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>