scsi: aacraid: Fix sync fibs time out on controller reset

After controller shutdown, all sync fibs time out due to not knowing
about the switch to INT-x mode

Fixed by replacing aac_src_access_devreg() to aac_set_intx_mode() call.

Cc: stable@vger.kernel.org
Fixes: 495c0217 (aacraid: MSI-x support)
Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Reviewed-by: David Carroll <David.Carroll@microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>