ARM: dts: imx6qdl-dhcom: Add DHSOM based DRC02 board

ARM: dts: imx6qdl-dhcom: Add DHSOM based DRC02 board

Add DT for DH DRC02 unit, which is a universal controller device.
The system has two ethernet ports, two CANs, RS485 and RS232, USB,
capacitive buttons and an OLED display.

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
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>