ARM: dts: imx6q-cm-fx6: remove iomuxc container node

The imx6q-cm-fx6 iomuxc container node is not required. Remove it.

Signed-off-by: Christopher Spinrath <christopher.spinrath@rwth-aachen.de>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>