VOL-1460 Updated to use a voltha-protos repo as source for protos

Change-Id: I6e88fb3bb16f91941abaad2f0a810ebc5aa29f36
diff --git a/python/adapters/openolt/openolt_platform.py b/python/adapters/openolt/openolt_platform.py
index 7032247..a52d653 100644
--- a/python/adapters/openolt/openolt_platform.py
+++ b/python/adapters/openolt/openolt_platform.py
@@ -14,8 +14,8 @@
 # limitations under the License.
 #
 
-from pyvoltha.protos.device_pb2 import Port
-import pyvoltha.protos.device_pb2 as dev_pb2
+from voltha_protos.device_pb2 import Port
+import voltha_protos.device_pb2 as dev_pb2
 
 """
 Encoding of identifiers