linux-imx

NVMe: add ->exit_hctx() hook

If we do teardown and setup of the queue and block related parts
of the driver, then we should clear nvmeq->hctx once we kill the
hardware queue.

Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>