IVGCVSW-4065 Add a RecordEvent function

 * Added RecordEvent utility function to the TimelineUtilityMethods
   class
 * Added new utility function to get a timestamp
 * Added unit tests

Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
Change-Id: Ia3f8fe7397915fa6c903ce0c0abab3047cea628c
diff --git a/src/profiling/ProfilingUtils.hpp b/src/profiling/ProfilingUtils.hpp
index fae1a83..74fc437 100644
--- a/src/profiling/ProfilingUtils.hpp
+++ b/src/profiling/ProfilingUtils.hpp
@@ -202,9 +202,11 @@
     using Exception::Exception;
 };
 
-}    // namespace profiling
+uint64_t GetTimestamp();
 
-}    // namespace armnn
+} // namespace profiling
+
+} // namespace armnn
 
 namespace std
 {