IVGCVSW-2375 Add ParseAddN function to TfParser

* Unit tests in AddN.cpp

Change-Id: Ifb2fa1051d5d92c5d9a5ca751abee4e81ebe39c9
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2bafd03..be68798 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -389,6 +389,7 @@
         list(APPEND unittest_sources
             src/armnnTfParser/test/Activations.cpp
             src/armnnTfParser/test/Addition.cpp
+            src/armnnTfParser/test/AddN.cpp
             src/armnnTfParser/test/BiasAdd.cpp
             src/armnnTfParser/test/BroadcastForAdd.cpp
             src/armnnTfParser/test/Convolution2d.cpp