Add support for ILI2117 touch controller. This controller is similar
to the ILI210x and ILI251x, except for the following differences:
- Reading out of touch data must happen at most 300 mS after the
  interrupt line was asserted. No command must be sent, the data
  are returned upon pure I2C read of 43 bytes long.
- Supports 10 simultaneous touch inputs.
- Touch data format is slightly different.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Rob Herring <robh@kernel.org> # for DT binding
Tested-by: Adam Ford <aford173@gmail.com> #imx6q-logicpd
Tested-by: Sven Van Asbroeck <TheSven73@gmail.com> # ILI2118A variant
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>