scsi: pm80xx: Event log size through sysfs

Added support to read event log size from MPI configuration table and
export through sysfs.

Signed-off-by: Deepak Ukey <deepak.ukey@microchip.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>