net: ravb: Simplify ravb_suspend()

As ravb_close() contains now the call to ravb_ptp_stop() for both ccc_gac
and gPTP aware platforms, there is no need to keep the separate call in
ravb_suspend(). Instead, move it to ravb_wol_setup(). In this way the
resulting code is cleaner.

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>