openflow_input: add BSN extensions to OF 1.4

I left out the following extensions that are no longer used or have been
superceded by the standard:

 - bsn_disable_split_horizon_check
 - bsn_role_status
 - bsn_global_vrf_allowed
diff --git a/openflow_input/bsn_span_destination b/openflow_input/bsn_span_destination
index 7fd900d..fd4f677 100644
--- a/openflow_input/bsn_span_destination
+++ b/openflow_input/bsn_span_destination
@@ -30,6 +30,7 @@
 // Copyright (c) 2011, 2012 Open Networking Foundation
 
 #version 4
+#version 5
 
 struct of_instruction_bsn_span_destination : of_instruction_bsn {
     uint16_t type == 65535;