mtip32xx: Implement timeout handler

Added timeout handler. Replaced blk_mq_end_request() with
blk_mq_complete_request() to avoid double completion of a request.

Signed-off-by: Selvan Mani <smani@micron.com>
Signed-off-by: Rajesh Kumar Sambandam <rsambandam@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>