IVGCVSW-1913: Fix for ValidationTest.concat_float_3_relaxed

* Added RefPermuteFloat16Workload to serve as a fallback when CL
  does not support the required permute configuration for FP16
* Move Half.hpp to armnnUtils as the utils library should not be
  including private header files from the armnn library

Change-Id: Ibf0f698451e8406f7ed7cce470dab60b6d16361d
diff --git a/src/backends/reference/workloads/RefConvertFp32ToFp16Workload.cpp b/src/backends/reference/workloads/RefConvertFp32ToFp16Workload.cpp
index efaaf8e..99e3541 100644
--- a/src/backends/reference/workloads/RefConvertFp32ToFp16Workload.cpp
+++ b/src/backends/reference/workloads/RefConvertFp32ToFp16Workload.cpp
@@ -5,12 +5,12 @@
 
 #include "RefConvertFp32ToFp16Workload.hpp"
 
-#include "Half.hpp"
 #include "FloatingPointConverter.hpp"
 #include "RefWorkloadUtils.hpp"
-
 #include "Profiling.hpp"
 
+#include "armnnUtils/Half.hpp"
+
 namespace armnn
 {