[media] media: i2c/ov5645: add the device tree binding document

* Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor

The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image sensor with

an active array size of 2592H x 1944V. It is programmable through a serial I2C

interface.

Required Properties:

- compatible: Value should be "ovti,ov5645".

- clocks: Reference to the xclk clock.

- clock-names: Should be "xclk".

- clock-frequency: Frequency of the xclk clock.

- enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds

  to the hardware pin PWDNB which is physically active low.

- reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to

  the hardware pin RESETB.

- vdddo-supply: Chip digital IO regulator.

- vdda-supply: Chip analog regulator.

- vddd-supply: Chip digital core regulator.

The device node must contain one 'port' child node for its digital output

video port, in accordance with the video interface bindings defined in

Documentation/devicetree/bindings/media/video-interfaces.txt.

Example:

	&i2c1 {

		...

		ov5645: ov5645@78 {

			compatible = "ovti,ov5645";

			reg = <0x78>;

			enable-gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>;

			reset-gpios = <&gpio5 20 GPIO_ACTIVE_LOW>;

			pinctrl-names = "default";

			pinctrl-0 = <&camera_rear_default>;

			clocks = <&clks 200>;

			clock-names = "xclk";

			clock-frequency = <23880000>;

			vdddo-supply = <&camera_dovdd_1v8>;

			vdda-supply = <&camera_avdd_2v8>;

			vddd-supply = <&camera_dvdd_1v2>;

			port {

				ov5645_ep: endpoint {

					clock-lanes = <1>;

					data-lanes = <0 2>;

					remote-endpoint = <&csi0_ep>;

				};

			};

		};

	};