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superceded by the standard: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_vrf_counter b/openflow_input/bsn_vrf_counter
index b638ff7..012d728 100644
--- a/openflow_input/bsn_vrf_counter
+++ b/openflow_input/bsn_vrf_counter
@@ -29,6 +29,7 @@
 // governing permissions and limitations under the EPL.
 
 #version 4
+#version 5
 
 enum ofp_bsn_vrf_counter_constants(wire_type=uint32_t) {
     OFP_BSN_VRF_ALL = 0xffffffff,