[POWERPC] 4xx: Add USB ehci-ppc-of dts bindings.

Adds EHCI OF bindings to documentation.
Signed-off-by: NValentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

Documentation/powerpc/booting-without-of.txt

@@ -57,6 +57,7 @@ Table of Contents
       n) 4xx/Axon EMAC ethernet nodes
       o) Xilinx IP cores
       p) Freescale Synchronous Serial Interface
+	  q) USB EHCI controllers
 
   VII - Specifying interrupt information for devices
     1) interrupts property
@@ -2775,6 +2776,33 @@ platforms are moved over to use the flattened-device-tree model.
 		interrupt-parent = < &ipic >;
         };
 
+    q) USB EHCI controllers
+
+    Required properties:
+      - compatible : should be "usb-ehci".
+      - reg : should contain at least address and length of the standard EHCI
+        register set for the device. Optional platform-dependent registers
+        (debug-port or other) can be also specified here, but only after
+        definition of standard EHCI registers.
+      - interrupts : one EHCI interrupt should be described here.
+    If device registers are implemented in big endian mode, the device
+    node should have "big-endian-regs" property.
+    If controller implementation operates with big endian descriptors,
+    "big-endian-desc" property should be specified.
+    If both big endian registers and descriptors are used by the controller
+    implementation, "big-endian" property can be specified instead of having
+    both "big-endian-regs" and "big-endian-desc".
+
+     Example (Sequoia 440EPx):
+	    ehci@e0000300 {
+		   compatible = "ibm,usb-ehci-440epx", "usb-ehci";
+		   interrupt-parent = <&UIC0>;
+		   interrupts = <1a 4>;
+		   reg = <0 e0000300 90 0 e0000390 70>;
+		   big-endian;
+	   };
+
+
    More devices will be defined as this spec matures.
 
 VII - Specifying interrupt information for devices