ieee1394: sbp2: fix bogus dma mapping

Need to use a PCI device, not a FireWire host device.  Problem found by
Andreas Schwab, mistake pointed out by Benjamin Herrenschmidt.
http://ozlabs.org/pipermail/linuxppc-dev/2006-December/029595.html



Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Andreas Schwab <schwab@suse.de>