Add dtsi for imx6q and imx6dl with non-common blocks moved into there.
Major differences between imx6dl and imx6q:
* Dual vs. Quad cores
* single vs. dual IPU
* 128 vs. 256 KB OCRAM
* imx6q: ECSPI5, OpenVG (GC355), SATA
* imx6dl: I2C4, PXP, EPDC, LCDIF
* iomuxc/pads definition
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>