net/mlx5: fix flow director delete with drop action
net/mlx5: fix flow director delete with drop action

Removing a flow director rule with a drop action ends by not removing it
due to a missing verbs drop specification in the conversion process between
the flow director and generic flow API.

Fixes: 4c3e9bcdd52e ("net/mlx5: support flow director")

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

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