net/bnxt: fix max rings calculation

net/bnxt: fix max rings calculation

Max Tx rings count could be lesser than max Rx rings in some
cases, so take this into account as well.

Account for stat contexts available(one for each ring) along with
no: of completion rings(one for each ring) to cap the max no: of
Tx /Rx rings that can be possibly created.

Fixes: f03e66cb64ce ("net/bnxt: limit queue count for NS3/Stingray devices")
Cc: stable@dpdk.org
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>