const_values: add enum, entry parameters

Currently defined parameters:
enum:
 - wire_type: type the values have on the wire (e.g., uint32_t)
 - bitmask: boolean flag if const is an enumeration (False)[Default], or
   a bitmask (True)
 - complete: whether the values listed are a complete enumeration of
   all possible values or not
entry:
 - virtual: whether the entry is a virtual, i.e., doesn't define
   a true enum value in its own right (true for _MASK_BIT values)
diff --git a/openflow_input/bsn_vport b/openflow_input/bsn_vport
index 0cf30bf..03b4b43 100644
--- a/openflow_input/bsn_vport
+++ b/openflow_input/bsn_vport
@@ -38,7 +38,7 @@
 // When the ingress or egress VID has this value, no outer tag should be used.
 // In this case, the corresponding TPID is ignored.
 
-enum ofp_bsn_vport_q_in_q_untagged {
+enum ofp_bsn_vport_q_in_q_untagged(wire_type=uint16_t, complete=False) {
     OF_BSN_VPORT_Q_IN_Q_UNTAGGED = 0xffff,
 };