MLCE-530 Add support for UnidirectionalSequenceLstm to RefWorkload

 * Add implementation of IsUnidirectionalSequenceLstmSupported to RefLayerSupport
 * Add RefUnidirectionalSequenceLstmWorkload
 * Refactor Lstm to be able to use for Lstm and SequenceLstm
 * Unit tests

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: Ibc066d213213a11b955dfefbe518de643298ba0c
diff --git a/src/backends/backendsCommon/test/CMakeLists.txt b/src/backends/backendsCommon/test/CMakeLists.txt
index 755cd21..4561fd7 100644
--- a/src/backends/backendsCommon/test/CMakeLists.txt
+++ b/src/backends/backendsCommon/test/CMakeLists.txt
@@ -169,6 +169,8 @@
     layerTests/SubtractionTestImpl.hpp
     layerTests/TransposeConvolution2dTestImpl.cpp
     layerTests/TransposeConvolution2dTestImpl.hpp
+    layerTests/UnidirectionalSequenceLstmTestImpl.cpp
+    layerTests/UnidirectionalSequenceLstmTestImpl.hpp
 )
 
 if (ARMNNREF)