ide: ->port_init_devs -> ->init_dev

Change ->port_init_devs method to take 'ide_drive_t *' as an argument
instead of 'ide_hwif_t *' and rename it to ->init_dev.

There should be no functional changes caused by this patch.

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