IVGCVSW-949 Refactor - clean up includes of ClWorkloadUtils.hpp

Move ClWorkloadUtils.hpp into ClWorkloads and reduce the number of places that include it

Change-Id: Iac661be34c185d6208ca75509155b049c24293ca
diff --git a/src/armnn/backends/ClWorkloads/ClActivationUint8Workload.cpp b/src/armnn/backends/ClWorkloads/ClActivationUint8Workload.cpp
index 07826b8..f39c856 100644
--- a/src/armnn/backends/ClWorkloads/ClActivationUint8Workload.cpp
+++ b/src/armnn/backends/ClWorkloads/ClActivationUint8Workload.cpp
@@ -9,6 +9,9 @@
 #include "backends/ArmComputeUtils.hpp"
 #include "backends/ClTensorHandle.hpp"
 #include "backends/CpuTensorHandle.hpp"
+
+#include "ClWorkloadUtils.hpp"
+
 namespace armnn
 {