scsi: core: Add counters for New Media and Power On/Reset UNIT ATTENTIONs

scsi: core: Add counters for New Media and Power On/Reset UNIT ATTENTIONs

The purpose of the counters is to enable all ULDs attached to a device to
find out that a New Media or/and Power On/Reset Unit Attentions has/have
been set, even if another ULD catches the Unit Attention as response to a
SCSI command.

The ULDs can read the counters and see if the values have changed from the
previous check.

Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Link: https://lore.kernel.org/r/20250120194925.44432-3-Kai.Makisara@kolumbus.fi
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Tested-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>