dt-bindings: arm: actions: Add S700 and CubieBoard7

Document the Actions Semi S700 SoC and the Cubietech CubieBoard7.

Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Andreas Färber <[e-mail]>

Documentation/devicetree/bindings/arm/actions.txt

···
  - LeMaker Guitar Base Board rev. B: "lemaker,guitar-bb-rev-b", "lemaker,guitar"
 
 
+S700 SoC
+========
+
+Required root node properties:
+
+- compatible :  must contain "actions,s700"
+
+
+Boards:
+
+Root node property compatible must contain, depending on board:
+
+ - Cubietech CubieBoard7: "cubietech,cubieboard7"
+
+
 S900 SoC
 ========