bnxt_en: Provision for an additional VNIC for ntuple filters

On newer chips that support the ring table index method for
ntuple filters, the current scheme of using the same VNIC for
both RSS and ntuple filters will not work in all cases.  An
ntuple filter can only be directed to a destination ring if
that destination ring is also in the RSS indirection table.

To support ntuple filters with any arbitratry RSS indirection
table that may only include a subset of the rings, we need to
use a separate VNIC for ntuple filters.

This patch provisions the additional VNIC.  The next patch will
allocate additional VNIC from firmware and set it up.

Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>