[bd-vif] all BD-VIF interfaces in state down if no efp present

[martink2]

Given Configuration:

bridge-domain 2140
 member BD-VIF 608
 member BD-VIF 4704

interface BD-VIF608
 no shutdown
 ...
interface BD-VIF4704
 no shutdown
 ...

Observed behaviour:

Bridge-domain 2140 (2 ports in all) 
State: UP                    Mac learning: Enabled
Aging-Timer: 300 second(s)
Maximum address limit: 65536
    BD-VIF608
    BD-VIF4704
   AED MAC address    Policy  Tag       Age  Pseudoport
   -   70DB.98BD.C87F to_bdi  static    0    BD-VIF608
   -   FA16.3E0F.F22E to_bdi  static    0    BD-VIF4704

show int BD-VIF608
BD-VIF608 is down, line protocol is down

show int BD-VIF4704
BD-VIF4704 is down, line protocol is down

Expected behaviour:

Bridge Domain is in up state so it is expected that both bdvif's would
be in up state as well.