ARM: dts: Add initial support for Wandboard Dual-Lite

Wandboard is a development board that has two variants: one version based
on mx6 dual lite and another one based on mx6 solo.

For more details about Wandboard, please refer to: http://www.wandboard.org/



Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>