arm64: dts: freescale: add initial support for verdin imx8m mini

This patch adds the device tree to support Toradex Verdin iMX8M Mini a
computer on module which can be used on different carrier boards.

The module consists of an NXP i.MX 8M Mini family SoC (either i.MX 8M
Mini Quad or 8M Mini DualLite), a PCA9450A PMIC, a Gigabit Ethernet PHY,
1 or 2 GB of LPDDR4 RAM, an eMMC, a TLA2024 ADC, an I2C EEPROM, an
RX8130 RTC, an optional SPI CAN controller plus an optional Bluetooth/
Wi-Fi module.

Anything that is not self-contained on the module is disabled by
default.

The device tree for the Dahlia includes the module's device tree and
enables the supported peripherals of the carrier board.

The device tree for the Verdin Development Board includes the module's
device tree as well as the Dahlia one as it is a superset and supports
almost all peripherals available.

So far there is no display functionality supported at all but basic
console UART, PCIe, USB host, eMMC and Ethernet and PCIe functionality
work fine.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>