Add support for Toradex Colibri iMX8DX SoM. As the i.MX8QXP variant is
already supported, update the description with i.MX8DX and add
'fsl,imx8dx' item as well.
Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>