qed: Add dcbnl support.

This patch adds the implementation for both cee/ieee dcbnl callbacks by
using the qed query/config APIs.

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