dt-bindings: clock: mediatek: add g3dsys bindings

MediaTek g3dsys controller

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The MediaTek g3dsys controller provides various clocks and reset controller to

the GPU.

Required Properties:

- compatible: Should be:

	- "mediatek,mt2701-g3dsys", "syscon":

		for MT2701 SoC

	- "mediatek,mt7623-g3dsys", "mediatek,mt2701-g3dsys", "syscon":

		for MT7623 SoC

- #clock-cells: Must be 1

- #reset-cells: Must be 1

The g3dsys controller uses the common clk binding from

Documentation/devicetree/bindings/clock/clock-bindings.txt

The available clocks are defined in dt-bindings/clock/mt*-clk.h.

Example:

g3dsys: clock-controller@13000000 {

	compatible = "mediatek,mt7623-g3dsys",

		     "mediatek,mt2701-g3dsys",

		     "syscon";

	reg = <0 0x13000000 0 0x200>;

	#clock-cells = <1>;

	#reset-cells = <1>;

};