netxen: enable ip addr hashing

NX3031 hardware requires local IP addresses for packet
accumulation (LRO). IP address hashing is required to
distinguish a local TCP flow from others (forwarded or
guest).

This patch adds listener for IP and netdev events and
configures IP address in the firmware.

Signed-off-by: Amit Kumar Salecha <amit@netxen.com>
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>