bnx2x: WoL only with current MAC address

In some cases with 57711E, depending on the functions unload sequence, other
functions MAC address could have been used to wake the system as well. Make sure
to block all but the current function if WoL is required by changing the mode
to single function WoL.

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