bnxt_en: Add SR-IOV support for 57500 chips.

There are some minor differences when assigning VF resources on the
new chips.  The MSIX (NQ) resource has to be assigned and ring group
is not needed on the new chips.

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