fix (brokton_brst2_airconditioner): correct hvac_mode dp name

Issue #4156

custom_components/tuya_local/devices/brokton_brst12_airconditioner.yaml

@@ -9,7 +9,7 @@ entities:
     dps:
       - id: 1
         type: boolean
-        name: switch
+        name: hvac_mode
         mapping:
           - dps_val: false
             value: "off"