Add variable_name to tensors

Signed-off-by: Tai Ly <tai.ly@arm.com>
Change-Id: Ia142c8b1a9e0869daefb3eef71100fd0c2a0effc
diff --git a/include/tosa_serialization_handler.h b/include/tosa_serialization_handler.h
index 875c9d1..e89ad0d 100644
--- a/include/tosa_serialization_handler.h
+++ b/include/tosa_serialization_handler.h
@@ -150,14 +150,16 @@
                             const flatbuffers::Vector<int32_t>* shape,
                             DType dtype,
                             const flatbuffers::Vector<uint8_t>* data,
-                            const bool variable    = false,
-                            const bool is_unranked = false);
+                            const bool variable                      = false,
+                            const bool is_unranked                   = false,
+                            const flatbuffers::String* variable_name = NULL);
     TosaSerializationTensor(const std::string& name,
                             const std::vector<int32_t>& shape,
                             DType dtype,
                             const std::vector<uint8_t>& data,
-                            const bool variable    = false,
-                            const bool is_unranked = false);
+                            const bool variable              = false,
+                            const bool is_unranked           = false,
+                            const std::string& variable_name = "");
     TosaSerializationTensor();
     ~TosaSerializationTensor();
 
@@ -186,6 +188,10 @@
     {
         return _is_unranked;
     }
+    const std::string GetVariableName() const
+    {
+        return _variable_name;
+    }
 
     // modifier
     void SetDtype(DType dtype)
@@ -225,6 +231,7 @@
     bool _variable;              /* is this a variable tensor */
     std::vector<uint8_t> _data;  /* data array */
     bool _is_unranked;           /* whether this is an unranked tensor */
+    std::string _variable_name;  /* name for variable tensors */
 };
 
 class TosaSerializationOperator