IVGCVSW-2333 Add ParseSub method to TfParser

* Also added unit test Sub.cpp

Change-Id: I6d23c11ae894ee433cd28ffdf0248b14e01b0131
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 152b195..1731576 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -411,7 +411,8 @@
             src/armnnTfParser/test/FullyConnected.cpp
             src/armnnTfParser/test/Constant.cpp
             src/armnnTfParser/test/TestMultiInputsOutputs.cpp
-            src/armnnTfParser/test/Squeeze.cpp)
+            src/armnnTfParser/test/Squeeze.cpp
+            src/armnnTfParser/test/Sub.cpp)
     endif()
 
     if(BUILD_TF_LITE_PARSER)