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superceded by the standard: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_arp_idle b/openflow_input/bsn_arp_idle
index 26cea92..16a1782 100644
--- a/openflow_input/bsn_arp_idle
+++ b/openflow_input/bsn_arp_idle
@@ -35,6 +35,7 @@
 // not remove the table entry on its own.
 
 #version 4
+#version 5
 
 struct of_bsn_arp_idle : of_bsn_header {
     uint8_t version;