IVGCVSW-6712 Move SubgraphView to backends include folder

 * Make subgraphview a public interface for backends.

Change-Id: I615a29ffec41e947215c3d29c2d7d214e327fb90
Signed-off-by: Francis Murtagh <francis.murtagh@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 629a798..5368401 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -185,6 +185,7 @@
     include/armnn/utility/PolymorphicDowncast.hpp
     include/armnn/utility/StringUtils.hpp
     include/armnn/utility/TransformIterator.hpp
+    include/armnn/backends/SubgraphView.hpp
     src/armnn/layers/LayerCloneBase.hpp
     src/armnn/layers/LayerWithParameters.hpp
     src/armnn/layers/ActivationLayer.hpp
@@ -386,7 +387,6 @@
     src/armnn/SerializeLayerParameters.cpp
     src/armnn/SerializeLayerParameters.hpp
     src/armnn/SubgraphView.cpp
-    src/armnn/SubgraphView.hpp
     src/armnn/SubgraphViewSelector.cpp
     src/armnn/SubgraphViewSelector.hpp
     src/armnn/Tensor.cpp