s390/vfio-ap: realize the VFIO_DEVICE_GET_IRQ_INFO ioctl

Realize the VFIO_DEVICE_GET_IRQ_INFO ioctl to retrieve the information for
the VFIO device request IRQ.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20230530223538.279198-2-akrowiak@linux.ibm.com


Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>