COMPMID-556 Add macro for checking graph's tensor object

Change-Id: I1de1c2932c9906b23b49e18bd82c173846d98723
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/93860
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Reviewed-by: Pablo Tello <pablo.tello@arm.com>
diff --git a/src/graph/Tensor.cpp b/src/graph/Tensor.cpp
index f85fe27..4db79e9 100644
--- a/src/graph/Tensor.cpp
+++ b/src/graph/Tensor.cpp
@@ -95,6 +95,11 @@
     return _tensor.get();
 }
 
+const arm_compute::ITensor *Tensor::tensor() const
+{
+    return _tensor.get();
+}
+
 const TensorInfo &Tensor::info() const
 {
     return _info;