ide: fix ide_register_hw() to check hwif->io_ports[]

hwif->hw.io_ports[] and hwif->io_ports[] should be the same but "4drives"
support and scc_pata host driver set only hwif->io_ports[].

To compensate for this check hwif->io_ports[] instead of hwif->hw.io_ports[]
in ide_register_hw() (instead of fixing "4drives" and scc_pata because hwif->hw
is to be removed).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>