staging: iio: tsl2x7x: add device tree documentation

Add device tree documentation for the tsl2x7x IIO driver.
Signed-off-by: Brian Masney <masneyb@onstation.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Mark Rutland <mark.rutland@arm.com>
CC: devicetree@vger.kernel.org
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/trivial-devices.txt

@@ -21,6 +21,16 @@ adi,adt7490		+/-1C TDM Extended Temp Range I.C
 adi,adxl345		Three-Axis Digital Accelerometer
 adi,adxl346		Three-Axis Digital Accelerometer (backward-compatibility value "adi,adxl345" must be listed too)
 ams,iaq-core		AMS iAQ-Core VOC Sensor
+amstaos,tsl2571		AMS/TAOS ALS and proximity sensor
+amstaos,tsl2671		AMS/TAOS ALS and proximity sensor
+amstaos,tmd2671		AMS/TAOS ALS and proximity sensor
+amstaos,tsl2771		AMS/TAOS ALS and proximity sensor
+amstaos,tmd2771		AMS/TAOS ALS and proximity sensor
+amstaos,tsl2572		AMS/TAOS ALS and proximity sensor
+amstaos,tsl2672		AMS/TAOS ALS and proximity sensor
+amstaos,tmd2672		AMS/TAOS ALS and proximity sensor
+amstaos,tsl2772		AMS/TAOS ALS and proximity sensor
+amstaos,tmd2772		AMS/TAOS ALS and proximity sensor
 at,24c08		i2c serial eeprom  (24cxx)
 atmel,at97sc3204t	i2c trusted platform module (TPM)
 capella,cm32181		CM32181: Ambient Light Sensor