IVGCVSW-3117 Rename RefMergerWorkload to RefConcatWorkload

Change-Id: Ifeb33db919ef77bf777e114f2d84b88fd595ca2c
Signed-off-by: Jim Flynn <jim.flynn@arm.com>
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index a297529..1d635aa 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -29,6 +29,7 @@
         workloads/RefBatchNormalizationUint8Workload.cpp \
         workloads/RefBatchToSpaceNdFloat32Workload.cpp \
         workloads/RefBatchToSpaceNdUint8Workload.cpp \
+        workloads/RefConcatWorkload.cpp \
         workloads/RefConstantWorkload.cpp \
         workloads/RefConvertFp16ToFp32Workload.cpp \
         workloads/RefConvertFp32ToFp16Workload.cpp \
@@ -50,7 +51,6 @@
         workloads/RefLstmWorkload.cpp \
         workloads/RefMeanFloat32Workload.cpp \
         workloads/RefMeanUint8Workload.cpp \
-        workloads/RefMergerWorkload.cpp \
         workloads/RefNormalizationFloat32Workload.cpp \
         workloads/RefPadWorkload.cpp \
         workloads/RefPermuteWorkload.cpp \