bnx2x: do not call link update without HW notification

Signed-off-by: Yaniv Rosner <yanivr@broadcom.com>
Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@conan.davemloft.net>