net/mlx5: Devcom, Infrastructure changes

Update devcom infrastructure to be more generic, without
depending on max supported ports definition or a device guid,
and also more encapsulated so callers don't need to pass
the register devcom component id per event call.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>