dt: Move device tree documentation out of powerpc directory

The device tree is used by more than just PowerPC.  Make the documentation
directory available to all.

v2: reorganized files while moving to create arch and driver specific
    directories.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

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

@@ -0,0 +1,81 @@
+Freescale SOC USB controllers
+
+The device node for a USB controller that is part of a Freescale
+SOC is as described in the document "Open Firmware Recommended
+Practice : Universal Serial Bus" with the following modifications
+and additions :
+
+Required properties :
+ - compatible : Should be "fsl-usb2-mph" for multi port host USB
+   controllers, or "fsl-usb2-dr" for dual role USB controllers
+   or "fsl,mpc5121-usb2-dr" for dual role USB controllers of MPC5121
+ - phy_type : For multi port host USB controllers, should be one of
+   "ulpi", or "serial". For dual role USB controllers, should be
+   one of "ulpi", "utmi", "utmi_wide", or "serial".
+ - reg : Offset and length of the register set for the device
+ - port0 : boolean; if defined, indicates port0 is connected for
+   fsl-usb2-mph compatible controllers.  Either this property or
+   "port1" (or both) must be defined for "fsl-usb2-mph" compatible
+   controllers.
+ - port1 : boolean; if defined, indicates port1 is connected for
+   fsl-usb2-mph compatible controllers.  Either this property or
+   "port0" (or both) must be defined for "fsl-usb2-mph" compatible
+   controllers.
+ - dr_mode : indicates the working mode for "fsl-usb2-dr" compatible
+   controllers.  Can be "host", "peripheral", or "otg".  Default to
+   "host" if not defined for backward compatibility.
+
+Recommended properties :
+ - interrupts : <a b> where a is the interrupt number and b is a
+   field that represents an encoding of the sense and level
+   information for the interrupt.  This should be encoded based on
+   the information in section 2) depending on the type of interrupt
+   controller you have.
+ - interrupt-parent : the phandle for the interrupt controller that
+   services interrupts for this device.
+
+Optional properties :
+ - fsl,invert-drvvbus : boolean; for MPC5121 USB0 only. Indicates the
+   port power polarity of internal PHY signal DRVVBUS is inverted.
+ - fsl,invert-pwr-fault : boolean; for MPC5121 USB0 only. Indicates
+   the PWR_FAULT signal polarity is inverted.
+
+Example multi port host USB controller device node :
+	usb@22000 {
+		compatible = "fsl-usb2-mph";
+		reg = <22000 1000>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupt-parent = <700>;
+		interrupts = <27 1>;
+		phy_type = "ulpi";
+		port0;
+		port1;
+	};
+
+Example dual role USB controller device node :
+	usb@23000 {
+		compatible = "fsl-usb2-dr";
+		reg = <23000 1000>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupt-parent = <700>;
+		interrupts = <26 1>;
+		dr_mode = "otg";
+		phy = "ulpi";
+	};
+
+Example dual role USB controller device node for MPC5121ADS:
+
+	usb@4000 {
+		compatible = "fsl,mpc5121-usb2-dr";
+		reg = <0x4000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupt-parent = < &ipic >;
+		interrupts = <44 0x8>;
+		dr_mode = "otg";
+		phy_type = "utmi_wide";
+		fsl,invert-drvvbus;
+		fsl,invert-pwr-fault;
+	};

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

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+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;
+   };