Mayborn GroClock: add missed alarm mode select

Skipped over this, as it didn't seem "primary". Forgot to add it as a
secondary entity later.

Issue #2601

custom_components/tuya_local/devices/mayborn_groclock.yaml

@@ -69,6 +69,21 @@ primary_entity:
       optional: true
       name: snooze
 secondary_entities:
+  - entity: select
+    name: Alarm mode
+    icon: "mdi:alarm"
+    category: config
+    dps:
+      - id: 101
+        type: string
+        name: option
+        mapping:
+          - dps_val: awake
+            value: Wake up
+          - dps_val: nap
+            value: Nap
+          - dps_val: asleep
+            value: Sleep
   - entity: select
     name: Music playback
     icon: "mdi:music"