bnxt_en: Set the db_offset on 57500 chips for the RDMA MSIX entries.

bnxt_en: Set the db_offset on 57500 chips for the RDMA MSIX entries.

The driver provides completion ring or NQ doorbell offset for each
MSIX entry requested by the RDMA driver.  The NQ offset on 57500
chips is different than legacy chips.  Set it correctly based on
chip type for correctness.  The RDMA driver is ignoring this field
for the 57500 chips so it is not causing any problem.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>