Currently the legacy ide driver defines several request types of it's own,
which is in the way of removing that field entirely.

Instead add a type field to struct ide_request and use that to distinguish
the different types of IDE-internal requests.

It's a bit of a mess, but so is the surrounding code..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJens Axboe <axboe@fb.com>