Add dehumidifier class to the Greenwind dehumidifier

The default class is humidifier. I'm not sure exactly what this changes.

custom_components/tuya_local/devices/greenwind_dehumidifier.yaml

@@ -1,6 +1,7 @@
 name: Greenwind Dehumidifier
 primary_entity:
   entity: humidifier
+  class: dehumidifier
   dps:
     - id: 1
       name: switch