[SCSI] fcoe: save gateway address when receiving FLOGI request

In point-to-point mode, we need to save the source MAC
from received FLOGI requests to use as the destination MAC
for all outgoing frames.  We stopped doing that at some point.

Use the lport_set_port_id method to catch incoming FLOGI frames
and pass them to fcoe_ctlr_recv_flogi() so it can save the source MAC.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>