ARM: dts: imx6qdl-apalis/-colibri: prevent 1.8V modes

Use no-1-8-v device tree property to indicate that the board does
not support 1.8V signaling. The property voltage-ranges seems not
appropriate in our case since we do not have level shifters in
place.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>