Device Tree Clock bindings for Marvell Berlin

This binding uses the common clock binding[1].

[1] Documentation/devicetree/bindings/clock/clock-bindings.txt

Clock related registers are spread among the chip control registers. Berlin
clock node should be a sub-node of the chip controller node. Marvell Berlin2
(BG2, BG2CD, BG2Q) SoCs share the same IP for PLLs and clocks, with some
minor differences in features and register layout.

Required properties:
- compatible: must be "marvell,berlin2-clk" or "marvell,berlin2q-clk"
- #clock-cells: must be 1
- clocks: must be the input parent clock phandle
- clock-names: name of the input parent clock
	Allowed clock-names for the reference clocks are
	"refclk" for the SoCs oscillator input on all SoCs,
	and SoC-specific input clocks for
	BG2/BG2CD: "video_ext0" for the external video clock input


Example:

chip_clk: clock {
	compatible = "marvell,berlin2q-clk";

	#clock-cells = <1>;
	clocks = <&refclk>;
	clock-names = "refclk";
};
