amd-xgbe: Change destination address filtering support

Currently the driver makes use of the additional mac address
registers in the hardware to provide perfect filtering.  The
hardware can also have a set of hash table registers that can
be used for imperfect filtering.  By using imperfect filtering
the additional mac address registers can be used for layer 2
filtering support.  Use the hash table registers if the device
has them.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>