ide-{cd,floppy,tape}: remove checking for drive->scsi

Remove checking for drive->scsi which is no longer set by IDE core code
(leave the flag since it will be re-used for generic ATAPI support).

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>