ARM: dts: imx6q-dhcom: Cleanup of the devicetrees

Following cleanups of the devicetrees done, no change in function:
- Remove parentheses from the license
- Update copyright date
- Alphabetical sorting
- Add comments
- Update pinctrl names
- Hex values in lower case
- Set 3rd values of fixed regulators gpio property to 0
- Replace interrupt type with a define
- Remove superfluous property max-speed from the fec node

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: kernel@dh-electronics.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Shawn Guo <shawnguo@kernel.org>