dt-bindings: phy: bindings document for common Broadcom SATA3 PHY driver

* Broadcom SATA3 PHY for STB

* Broadcom SATA3 PHY

Required properties:

- compatible: should be one or more of

     "brcm,bcm7425-sata-phy"

     "brcm,bcm7445-sata-phy"

     "brcm,iproc-ns2-sata-phy"

     "brcm,phy-sata3"

- address-cells: should be 1

- size-cells: should be 0

- reg: register range for the PHY PCB interface

- reg-names: should be "phy"

- reg: register ranges for the PHY PCB interface

- reg-names: should be "phy" and "phy-ctrl"

     The "phy-ctrl" registers are only required for

     "brcm,iproc-ns2-sata-phy".

Sub-nodes:

  Each port's PHY should be represented as a sub-node.

Sub-nodes required properties:

- reg: the PHY number

- phy-cells: generic PHY binding; must be 0

Optional:

- brcm,enable-ssc: use spread spectrum clocking (SSC) on this port

Sub-nodes optional properties:

- brcm,enable-ssc: use spread spectrum clocking (SSC) on this port

     This property is not applicable for "brcm,iproc-ns2-sata-phy".

Example:

	sata-phy@f0458100 {

		compatible = "brcm,bcm7445-sata-phy", "brcm,phy-sata3";

		reg = <0xf0458100 0x1e00>, <0xf045804c 0x10>;