IVGCVSW-4449 Add QLstm ref implementation

* Adds ref implemenation for new HAL 1.3
  operator, QLstm.
* Adds Layer and CreateWorkload unit tests.
* Adds WorkloadData validate for QLstm.

Signed-off-by: James Conroy <james.conroy@arm.com>
Change-Id: I8a721f07ff06105e6495a1a0561b9503aa8146dc
diff --git a/src/backends/reference/RefLayerSupport.hpp b/src/backends/reference/RefLayerSupport.hpp
index 30f45c3..eb89946 100644
--- a/src/backends/reference/RefLayerSupport.hpp
+++ b/src/backends/reference/RefLayerSupport.hpp
@@ -249,6 +249,16 @@
                              const TensorInfo& output,
                              Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
 
+    bool IsQLstmSupported(const TensorInfo& input,
+                          const TensorInfo& previousOutputIn,
+                          const TensorInfo& previousCellStateIn,
+                          const TensorInfo& outputStateOut,
+                          const TensorInfo& cellStateOut,
+                          const TensorInfo& output,
+                          const QLstmDescriptor& descriptor,
+                          const LstmInputParamsInfo& paramsInfo,
+                          Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsReshapeSupported(const TensorInfo& input,
                             const TensorInfo& output,
                             const ReshapeDescriptor& descriptor,