bnx2x: sfp+ Tx fault detection added

Adds the ability to identify sfp+ modules' Tx fault, and when such
occur shut down the link.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>