dt-bindings: iio: chemical: pms7003: extend supported sensors list

Add other sensors to the compatible list.
Signed-off-by: Tomasz Duszynski <tduszyns@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.txt

 * Plantower PMS7003 particulate matter sensor
 
 Required properties:
-- compatible: must be "plantower,pms7003"
+- compatible: must one of:
+   "plantower,pms1003"
+   "plantower,pms3003"
+   "plantower,pms5003"
+   "plantower,pms6003"
+   "plantower,pms7003"
+   "plantower,pmsa003"
 - vcc-supply: phandle to the regulator that provides power to the sensor
 
 Optional properties: