Revert "block: Provide blk_mq_sched_get_icq()"

This reverts commit 4896c4e64ba5d5d5acdbcf68c5910dd4f6d8fa62.

The helper is not needed any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211126115817.2087431-6-hch@lst.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>