bnx2x: Warpcore HW reset following fan failure

Put Warpcore in low power mode in case of fan failure to reduce heat.

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>