can: at91_can: register mb0 sysfs entry only on at91sam9263

This patch prepares the driver for the at91sam9X5 processors,
which don't have the mb0 bug.
(See commit 3a5655a5 for more details.)
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/at91_can.c

@@ -1257,7 +1257,6 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
 	dev->netdev_ops	= &at91_netdev_ops;
 	dev->irq = irq;
 	dev->flags |= IFF_ECHO;
-	dev->sysfs_groups[0] = &at91_sysfs_attr_group;
 
 	priv = netdev_priv(dev);
 	priv->can.clock.freq = clk_get_rate(clk);
@@ -1275,6 +1274,9 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
 
 	netif_napi_add(dev, &priv->napi, at91_poll, get_mb_rx_num(priv));
 
+	if (at91_is_sam9263(priv))
+		dev->sysfs_groups[0] = &at91_sysfs_attr_group;
+
 	dev_set_drvdata(&pdev->dev, dev);
 	SET_NETDEV_DEV(dev, &pdev->dev);