ARM: dts: imx7d: sbc-imx7: add basic board support

ARM: dts: imx7d: sbc-imx7: add basic board support

SBC-iMX7 is a single board computer designed for industrial
and embedded applications. It is based on the Freescale i.MX7
system-on-chip. SBC-iMX7 is implemented with the CL-SOM-iMX7
System-on-Module providing most of the functions, and SB-SOM-iMX7
carrier board providing additional peripheral functions and
connectors.

http://www.compulab.co.il/products/sbcs/sbc-imx7-freescale-i-mx-7-single-board-computer/

http://www.compulab.co.il/products/computer-on-modules/cl-som-imx7-freescale-i-mx-7-system-on-module/

Add basic board support, including SD card as a secondary boot and storage device

Signed-off-by: Ilya Ledvich <ilya@compulab.co.il>
Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>