arm64: dts: freescale: add support for i.MX8DXL EVK board

This is to support the EVK (Evaluation Kit Board) for the i.MX8DXL.
The patch has enabled the serial console, SD/EMMC interface, and
the eqos and fec ethernet network.

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>