IVGCVSW-3695 Add CL ArgMinMax workload

 * Also enabled copy to/from CL for Signed32.

Signed-off-by: James Conroy <james.conroy@arm.com>
Change-Id: I0113182891f9767de73f04dcd81252c84c996eda
diff --git a/src/backends/cl/workloads/ClWorkloads.hpp b/src/backends/cl/workloads/ClWorkloads.hpp
index cd6ca5f..dd8c699 100644
--- a/src/backends/cl/workloads/ClWorkloads.hpp
+++ b/src/backends/cl/workloads/ClWorkloads.hpp
@@ -7,6 +7,7 @@
 #include "ClAbsWorkload.hpp"
 #include "ClActivationWorkload.hpp"
 #include "ClAdditionWorkload.hpp"
+#include "ClArgMinMaxWorkload.hpp"
 #include "ClConstantWorkload.hpp"
 #include "ClBatchNormalizationFloatWorkload.hpp"
 #include "ClBatchToSpaceNdWorkload.hpp"