IVGCVSW-5300 Remove some boost::numeric_cast from armnn/backends

 * Replaced with armnn/utility/NumericCast.hpp
 * Some exclusions in reference backend
 * Excluded as requires float implementation in NumericCast.hpp

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: I9e4e9cd502c865452128fa04415fd6f250baa855
diff --git a/src/backends/cl/ClWorkloadFactory.cpp b/src/backends/cl/ClWorkloadFactory.cpp
index 4acfa57..f6650dc 100644
--- a/src/backends/cl/ClWorkloadFactory.cpp
+++ b/src/backends/cl/ClWorkloadFactory.cpp
@@ -11,6 +11,7 @@
 #include <armnn/Exceptions.hpp>
 #include <armnn/Utils.hpp>
 #include <armnn/utility/IgnoreUnused.hpp>
+#include <armnn/utility/NumericCast.hpp>
 #include <armnn/utility/PolymorphicDowncast.hpp>
 
 #include <backendsCommon/CpuTensorHandle.hpp>
@@ -130,7 +131,7 @@
     {
         // Arm compute indexes tensor coords in reverse order.
         unsigned int revertedIndex = subTensorShape.GetNumDimensions() - i - 1;
-        coords.set(i, boost::numeric_cast<int>(subTensorOrigin[revertedIndex]));
+        coords.set(i, armnn::numeric_cast<int>(subTensorOrigin[revertedIndex]));
     }
 
     const arm_compute::TensorShape parentShape = armcomputetensorutils::BuildArmComputeTensorShape(parent.GetShape());