3c589_cs: re-initialize the multicast in the tc589_reset

3c589_cs:
re-initialize the multicast in the tc589_reset,
and spin_lock the set_multicast_list function.

Signed-off-by: Ken Kawasaki <ken_kawasaki@spring.nifty.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>