IVGCVSW-3231 Add reference workload support for SpaceToDepth

* Added reference workload for SpaceToDepth
* Added unit tests for float32 & uint8
* Minor sort refactoring to RefWorkloads.hpp to alphabetical order

Change-Id: I2e01f8101650e2aae102a8a32bc0064f067141ab
Signed-off-by: Keith Davis <keith.davis@arm.com>
diff --git a/src/backends/reference/RefWorkloadFactory.cpp b/src/backends/reference/RefWorkloadFactory.cpp
index 29b2c52..1f241f0 100644
--- a/src/backends/reference/RefWorkloadFactory.cpp
+++ b/src/backends/reference/RefWorkloadFactory.cpp
@@ -298,6 +298,16 @@
     return std::make_unique<RefSpaceToBatchNdWorkload>(descriptor, info);
 }
 
+std::unique_ptr<IWorkload> RefWorkloadFactory::CreateSpaceToDepth(const armnn::SpaceToDepthQueueDescriptor& descriptor,
+    const armnn::WorkloadInfo& info) const
+{
+    if (IsFloat16(info))
+    {
+        return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
+    }
+    return std::make_unique<RefSpaceToDepthWorkload>(descriptor, info);
+}
+
 std::unique_ptr<IWorkload> RefWorkloadFactory::CreateFloor(const FloorQueueDescriptor& descriptor,
                                                           const WorkloadInfo& info) const
 {