IVGCVSW-2370 Code clean up after Equal operator implementation where necessary

StringMapping was located in the backendsCommon

Change-Id: I1c4a0bfca986722c721fcb2b460c03d6e1cd4568
diff --git a/src/backends/reference/workloads/RefElementwiseWorkload.hpp b/src/backends/reference/workloads/RefElementwiseWorkload.hpp
index 1b3200f..6dd6865 100644
--- a/src/backends/reference/workloads/RefElementwiseWorkload.hpp
+++ b/src/backends/reference/workloads/RefElementwiseWorkload.hpp
@@ -6,11 +6,11 @@
 #pragma once
 
 #include <armnn/Types.hpp>
-#include <backendsCommon/StringMapping.hpp>
 #include <backendsCommon/Workload.hpp>
 #include <backendsCommon/WorkloadData.hpp>
 #include "Maximum.hpp"
 #include "Minimum.hpp"
+#include "StringMapping.hpp"
 
 namespace armnn
 {