components/bt: fixed the invalid workqueue number for BTU thread in Bluedroid

There should be only one workqueue for BTU task. The queue length for the second workqueue of BTU can be uninitialized and caused memory overflow and corruption.

Closes https://github.com/espressif/esp-idf/issues/9507

components/bt/host/bluedroid/stack/btu/btu_init.c

@@ -48,7 +48,7 @@
 #define BTU_TASK_STACK_SIZE             (BT_BTU_TASK_STACK_SIZE + BT_TASK_EXTRA_STACK_SIZE)
 #define BTU_TASK_PRIO                   (BT_TASK_MAX_PRIORITIES - 5)
 #define BTU_TASK_NAME                   "BTU_TASK"
-#define BTU_TASK_WORKQUEUE_NUM          (2)
+#define BTU_TASK_WORKQUEUE_NUM          (1)
 #define BTU_TASK_WORKQUEUE0_LEN         (0)
 
 hash_map_t *btu_general_alarm_hash_map;