IVGCVSW-3975 Add reference workload for LOG_SOFTMAX

Signed-off-by: Aron Virginas-Tar <Aron.Virginas-Tar@arm.com>
Change-Id: I10bb7133e0e2d6d7199abdf39562b1226bbbd3e7
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index f45b015..49b07a4 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -35,6 +35,7 @@
         workloads/FullyConnected.cpp \
         workloads/Gather.cpp \
         workloads/InstanceNorm.cpp \
+        workloads/LogSoftmax.cpp \
         workloads/LstmUtils.cpp \
         workloads/Mean.cpp \
         workloads/Concatenate.cpp \
@@ -63,6 +64,7 @@
         workloads/RefGatherWorkload.cpp \
         workloads/RefInstanceNormalizationWorkload.cpp \
         workloads/RefL2NormalizationWorkload.cpp \
+        workloads/RefLogSoftmaxWorkload.cpp \
         workloads/RefLstmWorkload.cpp \
         workloads/RefMeanWorkload.cpp \
         workloads/RefNormalizationWorkload.cpp \