The current driver isn't taking advantage of a performance hint whereby
the initial data buffer descriptor can be placed in the WQE as well as
the SGL.

Add the logic to detect support for the feature and to use it when
supported.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>