dt-bindings: aspeed-scu: Add clock and reset 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>;

};