scsi: pm80xx: Add sysfs attribute to track iop1 count

scsi: pm80xx: Add sysfs attribute to track iop1 count

A new sysfs variable 'ctl_iop1_count' is being introduced that tells if
the controller is alive by indicating controller ticks. If on subsequent
run we see the ticks changing that indicates that controller is not
dead.

Using the 'ctl_iop1_count' sysfs variable we can see ticks incrementing:

    linux-9saw:~# cat  /sys/class/scsi_host/host*/ctl_iop1_count
    0x00000069
    0x0000006b
    0x0000006d
    0x00000072

Link: https://lore.kernel.org/r/20210415103352.3580-6-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>