m68k: Atari SCSI revival

SCSI should be working on a TT (but someone should really try!) but causes
trouble on a Falcon (as in: it ate a filesystem of mine) at least when
used concurrently with IDE. I have the notion it's because locking of the
ST-DMA interrupt by IDE is broken in 2.6 (the IDE driver always complains
about trying to release an already-released ST-DMA). Needs more work, but
that's on the IDE or m68k interrupt side rather than SCSI.

Signed-off-by: Michael Schmitz <schmitz@debian.org>
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>