Mantra fan: invert color_temp

Tuya values are relative to K, but we stil use mireds, which are backwards.

Issue #995

custom_components/tuya_local/devices/mantra_fan.yaml

@@ -137,6 +137,6 @@ secondary_entities:
         range:
           min: 0
           max: 1000
-
-
+        mapping:
+          - invert: true