scsi: aacraid: Fix DMAR issues with iommu=pt

scsi: aacraid: Fix DMAR issues with iommu=pt

BugLink: http://bugs.launchpad.net/bugs/1689980
The driver changed the DMA consistent map after consistent memory was
allocated, this invalidated the IOMMU identity mapping. The fix was to
make sure that we set the DMA consistent mask setting once depending on
the controller card.

Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Reviewed-by: Dave Carroll <david.carroll@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 96a580fcd7452dc4c136a8159501d4b60399f80d linux-next)
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>