[EP93xx_ETH]: Build fix after 2.6.24 NAPI changes.

Reported by rmk from kautobuild output:

drivers/net/arm/ep93xx_eth.c:420: error: implicit declaration of function '__netif_rx_schedule_prep'
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/arm/ep93xx_eth.c

@@ -417,7 +417,7 @@ static irqreturn_t ep93xx_irq(int irq, void *dev_id)
 
 	if (status & REG_INTSTS_RX) {
 		spin_lock(&ep->rx_lock);
-		if (likely(__netif_rx_schedule_prep(dev, &ep->napi))) {
+		if (likely(netif_rx_schedule_prep(dev, &ep->napi))) {
 			wrl(ep, REG_INTEN, REG_INTEN_TX);
 			__netif_rx_schedule(dev, &ep->napi);
 		}