IVGCVSW-2371 Add Rsqrt Ref implementation

*Added Unit Tests

Change-Id: I6cceb8e6dcda35ce08415f8e5ca86019a64d26e3
diff --git a/src/backends/reference/RefLayerSupport.hpp b/src/backends/reference/RefLayerSupport.hpp
index 3941f4b..188faa8 100644
--- a/src/backends/reference/RefLayerSupport.hpp
+++ b/src/backends/reference/RefLayerSupport.hpp
@@ -185,6 +185,10 @@
     bool IsResizeBilinearSupported(const TensorInfo& input,
                                    Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
 
+    bool IsRsqrtSupported(const TensorInfo& input,
+                          const TensorInfo& output,
+                          Optional<std::string&> reasonIfUnsupported = EmptyOptional()) const override;
+
     bool IsSoftmaxSupported(const TensorInfo& input,
                             const TensorInfo& output,
                             const SoftmaxDescriptor& descriptor,