In some rare cases, the driver can halt the controller. Add a reason code
describing why the controller was halted.  Store this reason code in a
controller register to aid in debugging the issue.

Link: https://lore.kernel.org/r/20210928235442.201875-4-don.brace@microchip.comReviewed-by: NScott Benesh <scott.benesh@microchip.com>
Reviewed-by: NScott Teel <scott.teel@microchip.com>
Reviewed-by: NMike McGowen <mike.mcgowen@microchip.com>
Acked-by: NJohn Donnelly <john.p.donnelly@oracle.com>
Signed-off-by: NMurthy Bhat <Murthy.Bhat@microchip.com>
Signed-off-by: NDon Brace <don.brace@microchip.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>