fix(inkbird_iic400_irrigationcontroller): timer is invalid for text

Translation key timer is only for number and time entities, text uses schedule
as they are usually more complex. But this one really is a timer setting, so
use an explicit icon instead.

custom_components/tuya_local/devices/inkbird_iic400_irrigationcontroller.yaml

@@ -28,7 +28,7 @@ entities:
   - entity: text
     name: Irrigation timer
     category: config
-    translation_key: timer
+    icon: "mdi:timer"
     hidden: true
     dps:
       - id: 45