bnx2x: fix possible deadlock in HC hw block

The possible deadlock (on 57710 devices only) will prevent from the
device to generate interrupts.

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