bnx2: Refine coalescing parameters.

- Set the USE_INT_PARAM bit so the rx-frames-irq and tx-frames-irq will take
  effect on 5709.
- Increase the default rx-frames to reduce interrupt count.
- Decrease the default rx-frames-irq and tx-frames-irq to catch more events
  during NAPI poll.

All these will reduce interrupts without affecting latency.

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