media: dt-bindings: media: video-i2c: add melexis mlx90640 documentation

Cc: devicetree@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/i2c/melexis,mlx90640.txt

+* Melexis MLX90640 FIR Sensor
+
+Melexis MLX90640 FIR sensor support which allows recording of thermal data
+with 32x24 resolution excluding 2 lines of coefficient data that is used by
+userspace to render processed frames.
+
+Required Properties:
+ - compatible : Must be "melexis,mlx90640"
+ - reg : i2c address of the device
+
+Example:
+
+	i2c0@1c22000 {
+		...
+		mlx90640@33 {
+			compatible = "melexis,mlx90640";
+			reg = <0x33>;
+		};
+		...
+	};