be2net: fix unnecessary access to hardware to get link, port info

Every time while doing ethtool->get_settings we are accessing
the hardware to get link status and port information.
This is not necessary.  We now use the cached copy for this info
and update it when the link status changes.

From: Suresh R <sureshr@serverengines.com>

Signed-off-by: Ajit Khaparde <ajitk@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>