Minor update

Change-Id: I24fc5be3c70d842323a916ddf95953b660d333c4
diff --git a/voltha/adapters/tibit_onu/tibit_onu.py b/voltha/adapters/tibit_onu/tibit_onu.py
index bc18dc7..8182494 100644
--- a/voltha/adapters/tibit_onu/tibit_onu.py
+++ b/voltha/adapters/tibit_onu/tibit_onu.py
@@ -597,7 +597,9 @@
 
             hw_vers = int(device.hardware_version, 16)
 
-            if hw_vers >= 0x170517:
+            if hw_vers >= 0x170618:
+                mcastLidx = 0x04bc
+            elif hw_vers >= 0x170517:
                 mcastLidx = 0x14bc
             else:
                 mcastLidx = 0x10bc