qed: Add support for static dcbx.

The patch adds driver support for static/local dcbx mode. In this mode
adapter brings up the dcbx link with locally configured parameters
instead of performing the dcbx negotiation with the peer. The feature
is useful when peer device/switch doesn't support dcbx.

Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>