Documentation: bindings: add the Berlin SATA PHY

Berlin SATA PHY

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Required properties:

- compatible: should be "marvell,berlin2q-sata-phy"

- address-cells: should be 1

- size-cells: should be 0

- phy-cells: from the generic PHY bindings, must be 1

- reg: address and length of the register

- clocks: reference to the clock entry

Sub-nodes:

Each PHY should be represented as a sub-node.

Sub-nodes required properties:

- reg: the PHY number

Example:

	sata_phy: phy@f7e900a0 {

		compatible = "marvell,berlin2q-sata-phy";

		reg = <0xf7e900a0 0x200>;

		clocks = <&chip CLKID_SATA>;

		#address-cells = <1>;

		#size-cells = <0>;

		#phy-cells = <1>;

		sata-phy@0 {

			reg = <0>;

		};

		sata-phy@1 {

			reg = <1>;

		};

	};