IVGCVSW-6847 replace armnn:Optional with arm::pipe::Optional in profiling code

Change-Id: I048c538d4f8c21770aec2b2751c934d9fa15a4dc
Signed-off-by: Jim Flynn <jim.flynn@arm.com>
diff --git a/src/profiling/ProfilingService.hpp b/src/profiling/ProfilingService.hpp
index 22349d0..e43642c 100644
--- a/src/profiling/ProfilingService.hpp
+++ b/src/profiling/ProfilingService.hpp
@@ -52,7 +52,7 @@
 
     ProfilingService(uint16_t maxGlobalCounterId,
                      IInitialiseProfilingService& initialiser,
-                     armnn::Optional<IReportStructure&> reportStructure = armnn::EmptyOptional())
+                     arm::pipe::Optional<IReportStructure&> reportStructure = arm::pipe::EmptyOptional())
         : m_Options()
         , m_TimelineReporting(false)
         , m_ProfilingConnectionFactory(new ProfilingConnectionFactory())