hisi_sas: Add abnormal irq handler

Add abnormal irq handler. This handler is concerned with phy down event.
Also add port formed and port deformed handlers.

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>