scsi: pm80xx: Handle non-fatal errors

scsi: pm80xx: Handle non-fatal errors

Firmware expects host driver to clear scratchpad rsvd 0 register after
non-fatal error is found.

This is done when firmware raises fatal error interrupt and indicates
non-fatal error. At this point firmware updates scratchpad rsvd 0 register
with non-fatal error value. Here host has to clear the register after
reading it during non-fatal errors.

Rename:

 - MSGU_HOST_SCRATCH_PAD_6 to MSGU_SCRATCH_PAD_RSVD_0

 - MSGU_HOST_SCRATCH_PAD_7 to MSGU_SCRATCH_PAD_RSVD_1

Link: https://lore.kernel.org/r/20220222092618.108198-1-Ajish.Koshy@microchip.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Ajish Koshy <Ajish.Koshy@microchip.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>