dt-bindings: phy: Move the Cadence D-PHY bindings

- one subnode per DSI device connected on the DSI bus. Each DSI device should

  contain a reg property encoding its virtual channel.

Cadence DPHY

============

Cadence DPHY block.

Required properties:

- compatible: should be set to "cdns,dphy".

- reg: physical base address and length of the DPHY registers.

- clocks: DPHY reference clocks.

- clock-names: must contain "psm" and "pll_ref".

- #phy-cells: must be set to 0.

Example:

	dphy0: dphy@fd0e0000{

		compatible = "cdns,dphy";

		reg = <0x0 0xfd0e0000 0x0 0x1000>;

		clocks = <&psm_clk>, <&pll_ref_clk>;

		clock-names = "psm", "pll_ref";

		#phy-cells = <0>;

	};

	dsi0: dsi@fd0c0000 {

		compatible = "cdns,dsi";

		reg = <0x0 0xfd0c0000 0x0 0x1000>;

Cadence DPHY

============

Cadence DPHY block.

Required properties:

- compatible: should be set to "cdns,dphy".

- reg: physical base address and length of the DPHY registers.

- clocks: DPHY reference clocks.

- clock-names: must contain "psm" and "pll_ref".

- #phy-cells: must be set to 0.

Example:

	dphy0: dphy@fd0e0000{

		compatible = "cdns,dphy";

		reg = <0x0 0xfd0e0000 0x0 0x1000>;

		clocks = <&psm_clk>, <&pll_ref_clk>;

		clock-names = "psm", "pll_ref";

		#phy-cells = <0>;

	};