dt-bindings: i2c: Add P8 OCC hwmon device documentation

Document the bindings for I2C-based OCC hwmon device.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/devicetree/bindings/i2c/ibm,p8-occ-hwmon.txt

+Device-tree bindings for I2C-based On-Chip Controller hwmon device
+------------------------------------------------------------------
+
+Required properties:
+ - compatible = "ibm,p8-occ-hwmon";
+ - reg = <I2C address>;			: I2C bus address
+
+Examples:
+
+    i2c-bus@100 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        clock-frequency = <100000>;
+        < more properties >
+
+        occ-hwmon@1 {
+            compatible = "ibm,p8-occ-hwmon";
+            reg = <0x50>;
+        };
+
+        occ-hwmon@2 {
+            compatible = "ibm,p8-occ-hwmon";
+            reg = <0x51>;
+        };
+    };