DT: Add documentation for cm36651 proximity/light sensor

This patch adds device tree binding documentation for CM36651 proximity/light sensor.

Signed-off-by: Beomho Seo <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

Documentation/devicetree/bindings/iio/light/cm36651.txt

···
+* Capella CM36651 I2C Proximity and Color Light sensor
+
+Required properties:
+- compatible: must be "capella,cm36651"
+- reg: the I2C address of the device
+- interrupts: interrupt-specifier for the sole interrupt
+	      generated by the device
+- vled-supply: regulator for the IR LED. IR_LED is a part
+	      of the cm36651 for proximity detection.
+	      As covered in ../../regulator/regulator.txt
+
+Example:
+
+	i2c_cm36651: i2c-gpio {
+		/* ... */
+
+		cm36651@18 {
+			compatible = "capella,cm36651";
+			reg = <0x18>;
+			interrupt-parent = <&gpx0>;
+			interrupts = <2 0>;
+			vled-supply = <&ps_als_reg>;
+		};
+
+		/* ... */
+	};

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 avago	Avago Technologies
 bosch	Bosch Sensortec GmbH
 brcm	Broadcom Corporation
+capella	Capella Microsystems, Inc
 cavium	Cavium, Inc.
 chrp	Common Hardware Reference Platform
 cirrus	Cirrus Logic, Inc.