ide: IDE_HFLAG_BOOTABLE -> IDE_HFLAG_NON_BOOTABLE

"bootable" should be the default behavior so replace
IDE_HFLAG_BOOTABLE host flag with IDE_HFLAG_NON_BOOTABLE.

There should be no functional changes caused by this patch.

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