dt-bindings: arm: fsl: add toradex,colibri-imx6ull

Add toradex,colibri-imx6ull for carrier board dts,
including aster, iris and iris-v2 device tree,
wifi and nonwifi variants for NAND and eMMC modules.

Signed-off-by: Denys Drozdov <denys.drozdov@toradex.com>
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>