IVGCVSW-1642 : adding IBackendInternal interface

Change-Id: Icd55fed8381af319f11b4cd977cf03103cdf1bd9
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 39d83c2..56b0935 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -150,6 +150,7 @@
     include/armnn/Descriptors.hpp
     include/armnn/DescriptorsFwd.hpp
     include/armnn/IRuntime.hpp
+    include/armnn/ILayerSupport.hpp
     include/armnn/INetwork.hpp
     include/armnn/Tensor.hpp
     include/armnn/TensorFwd.hpp