skge: restore rx multicast filter on resume and after config changes

Restore skge hardware registers for multicast filtering to their
appropriate values after system resume and after hardware restarts
that are done when changing certain settings.

Signed-off-by: Florian Zumbiehl <florz@florz.de>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>