ARM: dts: imx6dl-colibri: Move common nodes to SoM dtsi

The following two nodes define module level functionality, move
them from the carrier board dts file to the SoM file.
While at it, reorder the properties in the gpio-keys node alphabetical.

- gpio-keys defining the wakeup pin
- memory node

The atmel touchscreen node can be used on any carrier board.
Move it from the carrier board to the module-level device tree and
keep it disabled.
Set the default pinmuxing to the dedicated connector available
on newer carrier boards and rename the pinctrl labels specifying
the INT/Reset signal to a common pattern.
  pinctrl_atmel_conn - uses 107/106 pins as used on dedicated connector
  pinctrl_atmel_adap - uses 28/30 pins as used with jumper wires

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>