* Add struct ide_ioctl_devset representing ioctl device setting.

* Add ide_setting_ioctl() helper for matching given ioctl
  and its parameters against table of ioctl device settings.

* Convert ide_setting_ioctl() and idedisk_ioctl() to use
  ide_setting_ioctl().

* Un-export ide_setting_mtx.

While at it:

* {get,set}_lba_addressing() -> {get,set}_addressing()

There should be no functional changes caused by this patch.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>