phy: Add brcm,bcm63xx-usbh device tree binding

Add device tree binding for the BCM63xx USBH PHY.

The BCM63xx contains an USB host PHY that must be enabled and configured
for use with the EHCI/OHCI drivers.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>

Documentation/devicetree/bindings/phy/brcm,bcm63xx-usbh.txt

@@ -0,0 +1,30 @@
+* Broadcom USBH PHY for BCM63xx
+
+The BCM63xx contains an USB host PHY that must be enabled and configured
+for use with the EHCI/OHCI drivers.
+
+Required properties:
+- compatible: should be "brcm,bcm<soc>-usbh" followed by one of
+	"brcm,bcm6318-usbh" (for BCM6318)
+	"brcm,bcm6328-usbh" (for BCM6328, BCM63168, BCM63268, BCM6828, BCM68220)
+	"brcm,bcm6358-usbh" (for BCM6358)
+	"brcm,bcm6368-usbh" (for BCM6368, BCM6362, BCM6816)
+
+- reg: register range for the PHY interface
+- reg-names: should be "phy"
+- clocks: list of phandles to the two clocks for the PHY
+- clock-names: should be "usbh", "usb_ref"
+- power-domains: phandle to the power domain for the PHY
+- phy-cells: generic PHY binding; must be 0
+
+Example:
+
+usbh: usb-phy@10002700 {
+	compatible = "brcm,bcm63168-usbh", "brcm,bcm6328-usbh";
+	reg = <0x10002700 0x38>;
+	clocks = <&periph_clk 13>, <&timer_clk 18>;
+	clock-names = "usbh", "usb_ref";
+	resets = <&periph_soft_rst 6>;
+	power-domains = <&misc_iddq_ctrl 4>;
+	#phy-cells = <0>;
+};