Feyree EV portable: fix device class definition

PR #3294

custom_components/tuya_local/devices/feyree_ev_portable_charger.yaml

@@ -75,7 +75,7 @@ entities:
           - scale: 2
   - entity: binary_sensor
     name: Alarm event
-    device_class: problem
+    class: problem
     icon: 'mdi:alert-outline'
     dps:
       - id: 10