scsi: megaraid_sas: switch to generic DMA API

Switch from the legacy PCI DMA API to the generic DMA API.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>