ide: add Toshiba TC86C001 IDE driver (take 2)

This is the driver for the Toshiba TC86C001 GOKU-S PCI IDE controller,
completely reworked from the original brain-damaged Toshiba's 2.4 version.

This single channel UltraDMA/66 controller is very simple in programming,
yet Toshiba managed to plant many interesting bugs in it.  The particularly
nasty "limitation 5" (as they call the errata) caused me to abuse the IDE
core in a possibly most interesting way so far.  However, this is still
better than the #ifdef mess in drivers/ide/ide-io.c that the original
version included (well, it had much more mess)...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>