IVGCVSW-2915 Add Merge Layer and no-op factory method

Change-Id: I54549671e0d3b207904cf9796a843eb2b0a631f7
Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>
diff --git a/src/backends/backendsCommon/WorkloadFactory.hpp b/src/backends/backendsCommon/WorkloadFactory.hpp
index ed7303c..889bc9d 100644
--- a/src/backends/backendsCommon/WorkloadFactory.hpp
+++ b/src/backends/backendsCommon/WorkloadFactory.hpp
@@ -121,6 +121,9 @@
     virtual std::unique_ptr<IWorkload> CreateMemCopy(const MemCopyQueueDescriptor& descriptor,
                                                      const WorkloadInfo& info) const;
 
+    virtual std::unique_ptr<IWorkload> CreateMerge(const MergeQueueDescriptor& descriptor,
+                                                    const WorkloadInfo& info) const;
+
     virtual std::unique_ptr<IWorkload> CreateMerger(const MergerQueueDescriptor& descriptor,
                                                     const WorkloadInfo&          info) const;