dt-bindings: Update documentation for stingray SATA phy

Update BRCM SATA phy dt-binding documentation for stingray.
Signed-off-by: NSrinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: NRay Jui <ray.jui@broadcom.com>
Reviewed-by: NScott Branden <scott.branden@broadcom.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NRob Herring <rob@kernel.org>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/brcm-sata-phy.txt

@@ -7,12 +7,13 @@ Required properties:
      "brcm,iproc-ns2-sata-phy"
      "brcm,iproc-nsp-sata-phy"
      "brcm,phy-sata3"
+     "brcm,iproc-sr-sata-phy"
 - address-cells: should be 1
 - size-cells: should be 0
 - 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".
+     "brcm,iproc-ns2-sata-phy" and "brcm,iproc-sr-sata-phy".
 
 Sub-nodes:
   Each port's PHY should be represented as a sub-node.
@@ -23,8 +24,8 @@ Sub-nodes required properties:
 
 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" and
-     "brcm,iproc-nsp-sata-phy".
+     This property is not applicable for "brcm,iproc-ns2-sata-phy",
+     "brcm,iproc-nsp-sata-phy" and "brcm,iproc-sr-sata-phy".
 
 Example:
 	sata-phy@f0458100 {