Adds SemphrGetCountFromISR with QMsgWaitingFromISR (FreeRTOS#345)

* Adds SemphrGetCountFromISR with QMsgWaitingFromISR

Author: Rrojas93

.github/lexicon.txt

@@ -2440,6 +2440,7 @@ uxsavedmaskvalue
 uxsavedtaskstackpointer
 uxschedulersuspended
 uxsemaphoregetcount
+uxsemaphoregetcountfromisr
 uxstate
 uxstreambuffernumber
 uxtaskgetnumberoftasks

include/semphr.h

@@ -1172,4 +1172,18 @@ typedef QueueHandle_t SemaphoreHandle_t;
  */
 #define uxSemaphoreGetCount( xSemaphore )                uxQueueMessagesWaiting( ( QueueHandle_t ) ( xSemaphore ) )
 
+/**
+ * semphr.h
+ * <pre>
+ * UBaseType_t uxSemaphoreGetCountFromISR( SemaphoreHandle_t xSemaphore );
+ * </pre>
+ *
+ * If the semaphore is a counting semaphore then uxSemaphoreGetCountFromISR() returns
+ * its current count value.  If the semaphore is a binary semaphore then
+ * uxSemaphoreGetCountFromISR() returns 1 if the semaphore is available, and 0 if the
+ * semaphore is not available.
+ *
+ */
+#define uxSemaphoreGetCountFromISR( xSemaphore )                uxQueueMessagesWaitingFromISR( ( QueueHandle_t ) ( xSemaphore ) )
+
 #endif /* SEMAPHORE_H */