net: ll_temac: Cleanup multicast filter on change

Avoid leaving old address table entries when using multicast.  If more than
one multicast address were removed, only the first removed address would
actually be cleared.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>