Input: add support for ChipOne icn8318 based touchscreens

The ChipOne icn8318 is an i2c capacitive touchscreen controller typically
used in cheap android tablets, this commit adds a driver for it.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>