ARM: dts: imx6dl-colibri: Disable add-on accessories

ARM: dts: imx6dl-colibri: Disable add-on accessories

The Toradex Colibri family is composed of SoM that can be plugged in
various carrier board, with carrier boards allowing multiple optional
add-on (e.g. display, camera, ...).

Keep all the SoM specific part into the module .dtsi, disabling
everything that is not self-contained on the board. The carrier board
dts can reuse/enable anything that is defined in the module dtsi.
Additional device tree overlays can be used for any accessories that
are plugged in the carrier board.

Disable parallel RGB:
The parallel RGB interface (lcd_display) and all related nodes can
be enabled in an overlay if used. Keep all nodes disabled in the
module-level device tree.
Rename display interface node to match imx6qdl-apalis
to make it easier to use overlays.
The pwm-backlight binding now requires the power-supply property,
add it.

Disable stmpe touchscreen:
The touchscreen can be enabled in an overlay if used.
Add labels to the stmpe sub nodes.

Disable hdmi interface:
HDMI can be enabled in an overlay if used.

Update SPDX-License spelling to latest convention.
Update Copyright year.

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