net/mlx5: Delete redundant default assignment of runtime devlink params

Runtime devlink params always read their values from the get() callbacks.
Also, it is an error to set driverinit_value for params which don't
support driverinit cmode. Delete such assignments.

In addition, move the set of default matching mode inside eswitch code.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>