bnx2x: Increase DMAE max write size for 57711

Increase DMAE max write size for 57711 to the maximum allowed value.

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