IVGCVSW-2245 Add Minimum Layer and no-op Factory implementation

Change-Id: I03fa374fd9692d98257de709f8c3ad0a49c88b95
diff --git a/src/backends/cl/ClWorkloadFactory.cpp b/src/backends/cl/ClWorkloadFactory.cpp
index 42fb833..a710e66 100644
--- a/src/backends/cl/ClWorkloadFactory.cpp
+++ b/src/backends/cl/ClWorkloadFactory.cpp
@@ -326,4 +326,10 @@
     return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
 }
 
+std::unique_ptr<IWorkload> ClWorkloadFactory::CreateMinimum(const MinimumQueueDescriptor& descriptor,
+                                                            const WorkloadInfo& info) const
+{
+    return MakeWorkload<NullWorkload, NullWorkload>(descriptor, info);
+}
+
 } // namespace armnn