Implement bt_gatt_cb_unregister method for sys_slist_find_and_remove.

Signed-off-by: Zhijie Zhong <zhongzhijie1@xiaomi.com>

Author: zhongzhijie1

include/zephyr/bluetooth/gatt.h

@@ -622,6 +622,15 @@ static inline const char *bt_gatt_err_to_str(int gatt_err)
  */
 void bt_gatt_cb_register(struct bt_gatt_cb *cb);
 
+/** @brief Unregister GATT callbacks.
+ *
+ *  Unregister callbacks for monitoring the state of GATT. The callback
+ *  struct should be one that was previously registered.
+ *
+ *  @param cb Callback struct.
+ */
+void bt_gatt_cb_unregister(struct bt_gatt_cb *cb);
+
 /** @brief Register GATT authorization callbacks.
  *
  *  Register callbacks to perform application-specific authorization of GATT

subsys/bluetooth/host/gatt.c

@@ -1628,6 +1628,11 @@ void bt_gatt_cb_register(struct bt_gatt_cb *cb)
 	sys_slist_append(&callback_list, &cb->node);
 }
 
+void bt_gatt_cb_unregister(struct bt_gatt_cb *cb)
+{
+	sys_slist_find_and_remove(&callback_list, &cb->node);
+}
+
 #if defined(CONFIG_BT_GATT_DYNAMIC_DB)
 static void db_changed(void)
 {