net/mlx5e: Separate mlx5e_set_rx_mode_work and move caller to en_main

Separate mlx5e_set_rx_mode into two, and move caller to en_main while
keeping implementation in en_fs in the newly declared function
mlx5e_fs_set_rx_mode. This; to minimize the coupling of flow_steering
to priv.

Add a parallel boolean member vlan_strip_disable to
mlx5e_flow_steering that's updated similarly as its identical in priv,
thus making it possible to adjust the rx_mode work handler to current
changes.

Also, add state_destroy boolean to mlx5e_flow_steering struct which
replaces the old check : !test_bit(MLX5E_STATE_DESTROYING, &priv->state).
This state member is updated accordingly prior to
INIT_WORK(mlx5e_set_rx_mode_work), This is done for similar purposes as
mentioned earlier and to minimize argument passings.

Signed-off-by: Lama Kayal <lkayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>