Refactor inlined utility functions in NetworkUtils

Change-Id: I26fb13717f64c942b2648702c52be18be856042d
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6af71b..ce04bba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -256,6 +256,7 @@
     src/armnn/LoadedNetwork.hpp
     src/armnn/Network.cpp
     src/armnn/Network.hpp
+    src/armnn/NetworkUtils.cpp
     src/armnn/NetworkUtils.hpp
     src/armnn/Observable.cpp
     src/armnn/Observable.hpp