EMAC driver: bf537 MAC multicast hash filtering patch

The bf537 Ethernet MAC driver in the 2007R1.1-RC3 kernel (and the
current kernel) do not implement multicast hash filtering. This
is a performance problem if you have lots of multicast on your network.

This patch plugs the right bits into the multicast hash registers.

Signed-off-by: Aidan Williams <aidan@nicta.com.au>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>