Document: devicetree: add OF documents for arch-mmp

Add OF support in Document/devicetree directory.
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/arm/mrvl.txt

+Marvell Platforms Device Tree Bindings
+----------------------------------------------------
+
+PXA168 Aspenite Board
+Required root node properties:
+	- compatible = "mrvl,pxa168-aspenite", "mrvl,pxa168";

Documentation/devicetree/bindings/gpio/mrvl-gpio.txt

+* Marvell PXA GPIO controller
+
+Required properties:
+- compatible : Should be "mrvl,pxa-gpio" or "mrvl,mmp-gpio"
+- reg : Address and length of the register set for the device
+- interrupts : Should be the port interrupt shared by all gpio pins, if
+- interrupt-name : Should be the name of irq resource.
+  one number.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be one.  It is the pin number.
+
+Example:
+
+	gpio: gpio@d4019000 {
+		compatible = "mrvl,mmp-gpio", "mrvl,pxa-gpio";
+		reg = <0xd4019000 0x1000>;
+		interrupts = <49>, <17>, <18>;
+		interrupt-name = "gpio_mux", "gpio0", "gpio1";
+		gpio-controller;
+		#gpio-cells = <1>;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+      };

Documentation/devicetree/bindings/i2c/mrvl-i2c.txt

+* I2C
+
+Required properties :
+
+ - reg : Offset and length of the register set for the device
+ - compatible : should be "mrvl,mmp-twsi" where CHIP is the name of a
+   compatible processor, e.g. pxa168, pxa910, mmp2, mmp3.
+   For the pxa2xx/pxa3xx, an additional node "mrvl,pxa-i2c" is required
+   as shown in the example below.
+
+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.
+ - mrvl,i2c-polling : Disable interrupt of i2c controller. Polling
+   status register of i2c controller instead.
+ - mrvl,i2c-fast-mode : Enable fast mode of i2c controller.
+
+Examples:
+	twsi1: i2c@d4011000 {
+		compatible = "mrvl,mmp-twsi", "mrvl,pxa-i2c";
+		reg = <0xd4011000 0x1000>;
+		interrupts = <7>;
+		mrvl,i2c-fast-mode;
+	};
+	
+	twsi2: i2c@d4025000 {
+		compatible = "mrvl,mmp-twsi", "mrvl,pxa-i2c";
+		reg = <0xd4025000 0x1000>;
+		interrupts = <58>;
+	};
+

Documentation/devicetree/bindings/rtc/sa1100-rtc.txt

+* Marvell Real Time Clock controller
+
+Required properties:
+- compatible: should be "mrvl,sa1100-rtc"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- interrupts: Should be two. The first interrupt number is the rtc alarm
+  interrupt and the second interrupt number is the rtc hz interrupt.
+- interrupt-names: Assign name of irq resource.
+
+Example:
+	rtc: rtc@d4010000 {
+		compatible = "mrvl,mmp-rtc";
+		reg = <0xd4010000 0x1000>;
+		interrupts = <5>, <6>;
+		interrupt-name = "rtc 1Hz", "rtc alarm";
+	};

Documentation/devicetree/bindings/serial/mrvl-serial.txt

+PXA UART controller
+
+Required properties:
+- compatible : should be "mrvl,mmp-uart" or "mrvl,pxa-uart".