arm64: dts: freescale: add support for SolidRun i.MX8MP HummingBoard IIoT

arm64: dts: freescale: add support for SolidRun i.MX8MP HummingBoard IIoT

Introduce support for the SolidRun i.MX8MP HummingBoard IIoT platform.
This board is a new design based on the i.MX8MP System on Module and
does not share much hardware with previous HummingBoard variants.

It comes with some common features:
- 3x USB-3.0 Type A connector
- 2x 1Gbps RJ45 Ethernet
- USB Type-C Console Port
- microSD connector
- RTC with backup battery
- RGB Status LED
- 1x M.2 M-Key connector with PCI-E Gen. 3 x1
- 1x M.2 B-Key connector with USB-2.0/3.0 + SIM card holder
- 1x LVDS Display Connector
- 1x DSI Display Connector
- GPIO header
- 2x RS232/RS485 ports (configurable)
- 2x CAN

In addition there is a board-to-board expansion connector to support
custom daughter boards with access to SPI, a range of GPIOs and -
notably - CAN and UART. Both 2x CAN and 2x UART can be muxed either
to this b2b connector, or a terminal block connector on the base board.

The routing choice for UART and CAN is expressed through gpio
mux-controllers in DT and can be changed by applying dtb overlays.

Signed-off-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>