net: ravb: Simplify ravb_resume()

Remove explicit calls to functions that are called by ravb_open(). There is
no need to have them doubled now that the ravb_open() already contains
what is needed for the interface configuration. Along with it,
configurations needed by PTP were moved to ravb_wol_restore(). With this,
code in ravb_resume() becomes simpler.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>