ide-disk: fix __ide_do_rw_disk() to use ->OUTBSYNC

Fix __ide_do_rw_disk() to use ->OUTBSYNC instead of ->OUTB
(needed for pmac and scc_pata host drivers).

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>