IVGCVSW-2997 Refactor reference LSTM workload

Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>
Change-Id: I6883f878d9f701a55153292769d2fc0530d2529e
diff --git a/src/backends/reference/workloads/CMakeLists.txt b/src/backends/reference/workloads/CMakeLists.txt
index 596c099..b1cdef9 100644
--- a/src/backends/reference/workloads/CMakeLists.txt
+++ b/src/backends/reference/workloads/CMakeLists.txt
@@ -26,6 +26,7 @@
     FullyConnected.hpp
     Gather.cpp
     Gather.hpp
+    LstmUtils.hpp
     Maximum.hpp
     Merger.hpp
     Merger.cpp
@@ -80,8 +81,8 @@
     RefGatherWorkload.hpp
     RefL2NormalizationFloat32Workload.cpp
     RefL2NormalizationFloat32Workload.hpp
-    RefLstmFloat32Workload.cpp
-    RefLstmFloat32Workload.hpp
+    RefLstmWorkload.cpp
+    RefLstmWorkload.hpp
     RefMergerFloat32Workload.cpp
     RefMergerFloat32Workload.hpp
     RefMergerUint8Workload.cpp