New hardware supports a SLI-4 interface, but with a new if_type
variant of 6.

If_type=6 has a different PCI BAR map, separate EQ/CQ doorbells,
and some changes in doorbell formats.

Add the changes for the if_type into headers, adapter initialization
and control flows. Add new eq and cq handlers.
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>