net/bnxt: check FW capability for VLAN offloads

net/bnxt: check FW capability for VLAN offloads

VLAN offload capability may be disabled in the FW. The driver
should not attempt to override or utilize this feature in such
scenarios since it will not work as expected.

Fixes: 0a6d2a720078 ("net/bnxt: get device infos")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>