MLCE-82 Add Neon Mean support and unit tests

Factor out new BuildArmComputeReductionCoordinates function
from CL backend into ArmComputeTensorUtils.

Update NEON LayerSupport and WorkloadFactory objects

Change-Id: Icc975ec699199bffafbdb207323df509d35e1e04
diff --git a/src/backends/neon/workloads/NeonMeanWorkload.hpp b/src/backends/neon/workloads/NeonMeanWorkload.hpp
new file mode 100644
index 0000000..055b52a
--- /dev/null
+++ b/src/backends/neon/workloads/NeonMeanWorkload.hpp
@@ -0,0 +1,30 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#pragma once
+
+#include <backendsCommon/Workload.hpp>
+
+#include <arm_compute/runtime/NEON/functions/NEReduceMean.h>
+
+namespace armnn
+{
+
+arm_compute::Status NeonMeanWorkloadValidate(const TensorInfo& input,
+                                             const TensorInfo& output,
+                                             const MeanDescriptor& desc);
+
+class NeonMeanWorkload : public BaseWorkload<MeanQueueDescriptor>
+{
+public:
+    NeonMeanWorkload(const MeanQueueDescriptor& descriptor, const WorkloadInfo& info);
+
+    void Execute() const override;
+
+private:
+    mutable arm_compute::NEReduceMean m_Layer;
+};
+
+} //namespace armnn