IVGCVSW-2371 Add Rsqrt Ref implementation

*Added Unit Tests

Change-Id: I6cceb8e6dcda35ce08415f8e5ca86019a64d26e3
diff --git a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
index d4c5fe4..d6528bb 100644
--- a/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
+++ b/src/backends/backendsCommon/test/IsLayerSupportedTestImpl.hpp
@@ -378,6 +378,8 @@
 
 DECLARE_LAYER_POLICY_2_PARAM(Reshape)
 
+DECLARE_LAYER_POLICY_1_PARAM(Rsqrt)
+
 DECLARE_LAYER_POLICY_2_PARAM(Softmax)
 
 DECLARE_LAYER_POLICY_2_PARAM(SpaceToBatchNd)