ide: remove ide_wait/head_wait path in ide_do_drive_cmd

Now all the users of ide_do_drive_cmd using ide_wait/head_wait are
converted to use blk_execute_rq this removes the ide_wait/head_wait
path in ide_do_drive_cmd.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>