scsi: mpt3sas: Add support for PCIe Lane margin

PCIe Lane margin tool box request requires IEEE sgl's and hence driver
fills the SGL field with IEEE sgl's while issuing the PCIe Lane margin
ioctl request to the HBA firmware.

Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>