bnx2x: Supporting BCM8726 PHY

Also adding the ability to recognize the optic module and disable it if it is
not authorized for safety reasons - since this feature might upset some users
which are willing to take the risk, it is optional and can be disabled by
setting an nvram bit (or a trivial driver patch to set this bit).
This dual port PHY requires special handling if the ports are swapped.

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>