sh: revert dreamcast pci change

Commit e036eaa6 broke dreamcast pci, this
patch fixes that by reverting the dreamcast specific bits.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>