bnx2: Add ack parameter to bnx2_fw_sync().

ack=1 means wait for firmware acknowledgement, and ack=0
means don't wait.  All current callers will set it to 1.

In the next patch, new calls will set ack=0.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>