bnx2x: Clear latch indication on link reset

When using latch indication for link change notification, need to
clear it when port is unloaded, otherwise it might generate false
indication on next load.

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