ARM: socfpga: Add socfpga Ethernet filter attributes entries

This patch adds socfpga Ethernet filter attributes for multicast
and unicast filters per Synopsys Ethernet IP configuration chosen
by Altera for the Cyclone 5 and Arria SOC FPGAs.

Signed-off-by: Vince Bridgers <vbridgers2013@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>