bnx2x: Fix link down in 57712 following LFA

In case of link flap avoidance between PXE boot and bnx2x, set the appropriate
PHY DEVAD even if LFA kicks in.

Signed-off-by: Yaniv Rosner <yanivr@broadcom.com>
Signed-off-by: Barak Witkowski <barak@broadcom.com>
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>