[0.12.1 cherrypick] ORT scheduler fix (#347)

* Add scheduler property to ort_engine (#345)

* Update ort_engine.py

Author: mgoin

src/deepsparse/benchmark/ort_engine.py

@@ -186,6 +186,13 @@ def num_cores(self) -> int:
         """
         return self._num_cores if self._num_cores else NUM_CORES
 
+    @property
+    def scheduler(self):
+        """
+        :return: The kind of scheduler to execute with
+        """
+        return None
+
     def run(
         self,
         inp: List[numpy.ndarray],