usb: musb: dsps: dt binding - add resources, example

OMAP2+ family of devices are now obtaining resources via DT, earlier
it was obtained from hwmod. Update binding document accrodingly, while
at it add example.
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>

Documentation/devicetree/bindings/usb/am33xx-usb.txt

 AM33XX MUSB GLUE
  - compatible : Should be "ti,musb-am33xx"
+ - reg : offset and length of register sets, first usbss, then for musb instances
+ - interrupts : usbss, musb instance interrupts in order
  - ti,hwmods : must be "usb_otg_hs"
  - multipoint : Should be "1" indicating the musb controller supports
    multipoint. This is a MUSB configuration-specific setting.
@@ -12,3 +14,22 @@ AM33XX MUSB GLUE
    represents PERIPHERAL.
  - power : Should be "250". This signifies the controller can supply upto
    500mA when operating in host mode.
+
+Example:
+
+usb@47400000  {
+	compatible = "ti,musb-am33xx";
+	reg = <0x47400000 0x1000	/* usbss */
+	       0x47401000 0x800		/* musb instance 0 */
+	       0x47401800 0x800>;	/* musb instance 1 */
+	interrupts = <17		/* usbss */
+		      18		/* musb instance 0 */
+		      19>;		/* musb instance 1 */
+	multipoint = <1>;
+	num-eps = <16>;
+	ram-bits = <12>;
+	port0-mode = <3>;
+	port1-mode = <3>;
+	power = <250>;
+	ti,hwmods = "usb_otg_hs";
+};