Drop Documentation/ide/

Drop all Documentation/ide/ since IDE support was deleted by
Christoph Hellwig <hch@lst.de>, Jun 16 2021.

Fixes: b7fb14d3 ("ide: remove the legacy ide driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>