IVGCVSW-3606 Support memory import for Reference backend

Signed-off-by: Ferran Balaguer <ferran.balaguer@arm.com>
Change-Id: I94bd191f88e0911ad4e4727610e81cd7afa95512
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index b212995..a8df565 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -14,6 +14,7 @@
         RefTensorHandle.cpp \
         RefWorkloadFactory.cpp \
         RefRegistryInitializer.cpp \
+        RefTensorHandleFactory.cpp \
         workloads/Activation.cpp \
         workloads/BatchNormImpl.cpp \
         workloads/BatchToSpaceNd.cpp \