[SCSI] fcoe: removes default sw transport code file fcoe_sw.c

Moves only required code from fcoe_sw.c to libfcoe.c towards having
just one source file for fcoe module, this gets rid off default sw
transport code in a separate fcoe_sw.c file.

Very minor renaming along this move, dropped _sw_ or _SW_ use
in names and replaced them by _if_ as a auxiliary interface
functions. Now some of these funcs can be removed or merged with
other func after fcoe transport is gone, but that should be
in another patch to keep this patch simple.

Now the libfcoe.c file name for fcoe module doesn't go along well,
so the libfcoe.c file renaming to fcoe.c as the only single fcoe
module file is done in next patch to keep this patch clean
and small for review.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>