BCom camera: add enum class to SD status sensor.

Now that mapped values were added in the previous commit, the sensor needs
to be of class enum to fit HA's expectations.

Issue #2835

custom_components/tuya_local/devices/bcom_intercom_camera.yaml

@@ -97,6 +97,7 @@ entities:
             value: "On"
   - entity: sensor
     name: SD status
+    class: enum
     category: diagnostic
     dps:
       - id: 110