net/mlx5: E-Switch, Update VF vports config when num of VFs changed

Currently, ECPF eswitch manager does one-time only configuration for
VF vports when device switches to offloads mode. However, when num of
VFs changed from host side, driver doesn't update VF vports
configurations.

Hence, perform VFs vport configuration update whenever num_vfs change
event occurs.

Signed-off-by: Bodong Wang <bodong@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>