mlx5: process offload flags only when requested
mlx5: process offload flags only when requested

Improve performance by processing offloads only when requested by the
application.

Signed-off-by: Nelio Laranjeiro <2f8dd9032d5b85ca4b53dec8ce664eb6998836be@6wind.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk