arm64: dts: imx8mm: Add support for emtrion emCON-MX8M Mini
This patch adds support for the emtrion GmbH emCON-MX8M Mini modules.
They are available with NXP i.MX 8M Mini equipped with 2 or 4 GB Memory.
The devicetree imx8mm-emcon.dtsi is the common part providing all
module components and the basic support for the SoC. The support for the
avari baseboard in the developer-kit configuration is provided by the
emcon-avari dts files.