FC Discovery changes

- Treat received PLOGI while logged in as a relogin (unregister and reregister).
- Added a timer to delay Nport discovery when clean bit is cleared and Fabric
  portname/nodename/FCID is changed.
- Invalidate Port's DID when receiving PLOGI from p2p port with CONFIG_PORT
  mailbox command.
Signed-off-by: Alex Iannicelli <alex.iannicelli@emulex.com>
Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>