New if_type=6 adapters support an additional BAR that provides
apertures to allow direct WQE to adapter push support - termed
Direct Packet Push (DPP). WQ creation differs slightly to ask for
a WQ to be DPP-ized. When submitting a WQE to a DPP WQ, it is
submitted to the host memory for the WQ normally, but is also
written by the host cpu directly to a BAR aperture.  Write buffer
coalescing in hardware is (hopefully) turned on, enabling single
pci write operation support. The doorbell is thing rung to indicate
the WQE is available and was pushed to the aperture.

This patch:
- Updates the WQ Create commands for the DPP options
- Adds the bar mapping for if_type=6 DPP bar
- Adds the WQE pushing to the DDP aperture received from WQ create
- Adds a new module parameter to disable DPP operation if desired.
  Default is enabled.
Signed-off-by: NDick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>