IVGCVSW-6856 Add GATHERNd FrontEnd and Ref Implementation

* Add front end
* Add reference workload
* Add unit tests
* Add EndToEnd test

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: I4cebd17b18476df86162e2dda3366c10e80bd2f8
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 60e0e52..d3d1fac 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -244,6 +244,8 @@
     src/armnn/layers/FullyConnectedLayer.cpp
     src/armnn/layers/GatherLayer.cpp
     src/armnn/layers/GatherLayer.hpp
+    src/armnn/layers/GatherNdLayer.cpp
+    src/armnn/layers/GatherNdLayer.hpp
     src/armnn/layers/InputLayer.hpp
     src/armnn/layers/InputLayer.cpp
     src/armnn/layers/InstanceNormalizationLayer.hpp