Add support for Toradex Colibri iMX8DX SoM and Aster, Evaluation Board v3,
Iris and Iris v2 carrier boards the module can be mated in.
This SoM is a variant of the already supported Colibri iMX8QXP, using an
NXP i.MX8DX SoC instead of i.MX8QXP.

Link: https://www.toradex.com/computer-on-modules/colibri-arm-family/nxp-imx-8xSigned-off-by: Hiago De Franco <hiago.franco@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>