scsi: mpi3mr: Add io_uring interface support in I/O-polled mode

Add support for the io_uring interface in I/O-polled mode.

This feature is disabled in the driver by default. To enable the feature, a
module parameter "poll_queues" has to be set with the desired number of
polling queues.

When the feature is enabled, the driver reserves a certain number of
operational queue pairs for the poll_queues either from the available queue
pairs or creates additional queue pairs based on the operational queue
availability.

The Polling queues will have corresponding IRQ and ISR functions as similar
to default queues. However, the IRQ line is disabled by the driver for
poll_queues.

Link: https://lore.kernel.org/r/20211220141159.16117-22-sreekanth.reddy@broadcom.com
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>