scsi: cxlflash: Select IRQ_POLL

scsi: cxlflash: Select IRQ_POLL

BugLink: http://bugs.launchpad.net/bugs/1702521
The driver now uses IRQ_POLL and needs to select it to avoid the
following build error.

ERROR: ".irq_poll_complete" [drivers/scsi/cxlflash/cxlflash.ko] undefined!
ERROR: ".irq_poll_sched" [drivers/scsi/cxlflash/cxlflash.ko] undefined!
ERROR: ".irq_poll_disable" [drivers/scsi/cxlflash/cxlflash.ko] undefined!
ERROR: ".irq_poll_init" [drivers/scsi/cxlflash/cxlflash.ko] undefined!

Fixes: cba06e6de403 ("scsi: cxlflash: Implement IRQ polling for RRQ processing")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 07cc1ccfb84320582c9ac389a21cd81df82bc123)
Signed-off-by: Victor Aoqui <victora@linux.vnet.ibm.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>