net/mlx5e: Minimize mlx5e_{open/close}_locked

mlx5e_redirect_rqts_to_{channels,drop} and mlx5e_{add,del}_sqs_fwd_rules
and Set real num tx/rx queues belong to
mlx5e_{activate,deactivate}_priv_channels, for that we move those functions
and minimize mlx5e_open/close flows.

This will be needed in downstream patches to replace old channels with new
ones without the need to call mlx5e_close/open.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>