dt-bindings: aspeed-scu: Add clock and reset properties

Signed-off-by: NJoel Stanley <joel@jms.id.au>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Documentation/devicetree/bindings/mfd/aspeed-scu.txt

@@ -9,10 +9,16 @@ Required properties:
 		"aspeed,g5-scu", "syscon", "simple-mfd"
 
 - reg:		contains the offset and length of the SCU memory region
+- #clock-cells: should be set to <1> - the system controller is also a
+	clock provider
+- #reset-cells: should be set to <1> - the system controller is also a
+	reset line provider
 
 Example:
 
 syscon: syscon@1e6e2000 {
 	compatible = "aspeed,ast2400-scu", "syscon", "simple-mfd";
 	reg = <0x1e6e2000 0x1a8>;
+	#clock-cells = <1>;
+	#reset-cells = <1>;
 };