IVGCVSW-4209 Create a public API for the ArmNN Utils

 * Moved the relevant armnnUtils headers to the new location:
   include/armnnUtils
 * Update the header usage throughout the source code

!android-nn-driver:2387

Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
Change-Id: I2ba15cebcacafad2b5a1a7b9c3312ffc585e09d6
diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index 5a84d8a..05684dc 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -6,17 +6,20 @@
 #include "RefLayerSupport.hpp"
 #include "RefBackendId.hpp"
 
-#include <DataLayoutIndexed.hpp>
-#include <InternalTypes.hpp>
-#include <LayerSupportCommon.hpp>
-
 #include <armnn/Types.hpp>
 #include <armnn/Descriptors.hpp>
 #include <armnn/BackendRegistry.hpp>
 
+#include <armnnUtils/DataLayoutIndexed.hpp>
+
+#include <InternalTypes.hpp>
+#include <LayerSupportCommon.hpp>
+
 #include <backendsCommon/LayerSupportRules.hpp>
+
 #include <backendsCommon/test/WorkloadTestUtils.hpp>
 
+#include <boost/cast.hpp>
 #include <boost/core/ignore_unused.hpp>
 
 #include <vector>