ARM: dts: compulab: add new board description

Add description for newly introduced Compulab devices:
- CL-SOM-iMX7
- SBC-iMX7
Signed-off-by: Ilya Ledvich <ilya@compulab.co.il>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/arm/compulab-boards.txt

-CompuLab SB-SOM is a multi-module baseboard capable of carrying CM-T43, CM-T54,
-and CM-QS600 modules with minor modifications to the SB-SOM assembly.
+CompuLab SB-SOM is a multi-module baseboard capable of carrying:
+ - CM-T43
+ - CM-T54
+ - CM-QS600
+ - CL-SOM-AM57x
+ - CL-SOM-iMX7
+modules with minor modifications to the SB-SOM assembly.
 
 Required root node properties:
     - compatible = should be "compulab,sb-som"
+
+Compulab CL-SOM-iMX7 is a miniature System-on-Module (SoM) based on
+Freescale i.MX7 ARM Cortex-A7 System-on-Chip.
+
+Required root node properties:
+    - compatible = "compulab,cl-som-imx7", "fsl,imx7d";
+
+Compulab SBC-iMX7 is a single board computer 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.
+
+Required root node properties:
+    - compatible = "compulab,sbc-imx7", "compulab,cl-som-imx7", "fsl,imx7d";