IVGCVSW-1813 - Add MeanLayer
 * add MeanLayer functionalities
 * modify MeanQueueDescriptor to use parameter
 * add IsMeanSupported placeholder for all backends

Change-Id: Ic69a34a61df667849977aad9b38f9a01eef565b5
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4453a85..7656c5d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -305,6 +305,8 @@
     src/armnn/layers/L2NormalizationLayer.cpp
     src/armnn/layers/LstmLayer.cpp
     src/armnn/layers/LstmLayer.hpp
+    src/armnn/layers/MeanLayer.hpp
+    src/armnn/layers/MeanLayer.cpp
     src/armnn/layers/MemCopyLayer.hpp
     src/armnn/layers/MemCopyLayer.cpp
     src/armnn/layers/MergerLayer.hpp