ARM: dts: imx6dl: plym2m, prtvt7, victgo: make use of new resistive-adc-touch driver

The tsc2046 is an ADC used as touchscreen controller. To share as mach
code as possible, we should use it as actual ADC + virtual touchscreen
controller.
With this patch we make use of the new kernel IIO and HID infrastructure.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>