ide: remove the legacy ide driver

The legay ide driver has been replace with libata starting in 2003 and has
been scheduled for removal for a while.  Finally kill it off so that we
can start cleaning up various bits of cruft it forced on the block layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>