[SCSI] libfcoe: fcoe: fnic: change fcoe_ctlr_init interface to specify mode

There are three modes that libfcoe currently supports, and a new one
is coming.  Change the fcoe_ctlr_init() interface to add the mode
desired.  This should not change any functionality.

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>