USB: ohci: da8xx: Add devicetree bindings

This patch documents the device tree bindings required for
the ohci controller found in TI da8xx family of SoC's

Cc: robh+dt@kernel.org
Cc: mark.rutland@arm.com
Cc: devicetree@vger.kernel.org
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAxel Haslam <ahaslam@baylibre.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/ohci-da8xx.txt

+DA8XX USB OHCI controller
+
+Required properties:
+
+ - compatible: Should be "ti,da830-ohci"
+ - reg:        Should contain one register range i.e. start and length
+ - interrupts: Description of the interrupt line
+ - phys:       Phandle for the PHY device
+ - phy-names:  Should be "usb-phy"
+
+Optional properties:
+ - vbus-supply: phandle of regulator that controls vbus power / over-current
+
+Example:
+
+ohci: usb@0225000 {
+        compatible = "ti,da830-ohci";
+        reg = <0x225000 0x1000>;
+        interrupts = <59>;
+        phys = <&usb_phy 1>;
+        phy-names = "usb-phy";
+        vbus-supply = <&reg_usb_ohci>;
+};