Fix MISRA_C_2012 rule 8.4 violation (#844)

Fix MISRA_C_2012 rule 8.4 violation

queue.c

@@ -165,6 +165,10 @@ typedef xQUEUE Queue_t;
 /* The queue registry is simply an array of QueueRegistryItem_t structures.
  * The pcQueueName member of a structure being NULL is indicative of the
  * array position being vacant. */
+
+/* MISRA Ref 8.4.2 [Declaration shall be visible] */
+/* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-84 */
+/* coverity[misra_c_2012_rule_8_4_violation] */
     PRIVILEGED_DATA QueueRegistryItem_t xQueueRegistry[ configQUEUE_REGISTRY_SIZE ];
 
 #endif /* configQUEUE_REGISTRY_SIZE */