qed: add support for link pause configuration.

The APIs for making this sort of configuration [e.g., via ethtool] are
already present in qede, but the current configuration flow in qed doesn't
respect it.

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>