net/mlx5e: E-Switch, Initialize E-Switch for eswitch manager

Initialize eswitch instance for a function which is eswitch manager
but not a vport group manager.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>