ARM: dts: imx: Add support for Apalis Evaluation Board v1.2

Add support for the new Apalis Evaluation Board v1.2. Because
only the imx6q-apalis-eval.dts was available, the imx6q-apalis-eval.dtsi
has been created which has common hardware configurations for v1.0, v1.1
and v1.2. Both imx6q-apalis-eval.dts and imx6q-apalis-eval-v1.2.dts
files include imx6q-apalis-eval.dtsi.

Versions 1.0 and 1.1 are compatible with each other and should
use imx6q-apalis-eval.dts file. Now for v1.2, the new device-tree file
should be used.

Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Hiago De Franco <hiago.franco@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>