ARM: dts: imx6: Add support for Toradex Ixora carrier board

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>