net: use core MTU range checking in wireless drivers

- set max_mtu in wil6210 driver
- set max_mtu in atmel driver
- set min/max_mtu in cisco airo driver, remove airo_change_mtu
- set min/max_mtu in ipw2100/ipw2200 drivers, remove libipw_change_mtu
- set min/max_mtu in p80211netdev, remove wlan_change_mtu
- set min/max_mtu in net/mac80211/iface.c and remove ieee80211_change_mtu
- set min/max_mtu in wimax/i2400m and remove i2400m_change_mtu
- set min/max_mtu in intersil/hostap and remove prism2_change_mtu
- set min/max_mtu in intersil/orinoco
- set min/max_mtu in tty/n_gsm and remove gsm_change_mtu

CC: netdev@vger.kernel.org
CC: linux-wireless@vger.kernel.org
CC: Maya Erez <qca_merez@qca.qualcomm.com>
CC: Simon Kelley <simon@thekelleys.org.uk>
CC: Stanislav Yakovlev <stas.yakovlev@gmail.com>
CC: Johannes Berg <johannes@sipsolutions.net>
CC: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wireless/atmel/atmel.c b/drivers/net/wireless/atmel/atmel.c
index bf2e9a0..eb92d5a 100644
--- a/drivers/net/wireless/atmel/atmel.c
+++ b/drivers/net/wireless/atmel/atmel.c
@@ -1295,14 +1295,6 @@ static struct iw_statistics *atmel_get_wireless_stats(struct net_device *dev)
 	return &priv->wstats;
 }
 
-static int atmel_change_mtu(struct net_device *dev, int new_mtu)
-{
-	if ((new_mtu < 68) || (new_mtu > 2312))
-		return -EINVAL;
-	dev->mtu = new_mtu;
-	return 0;
-}
-
 static int atmel_set_mac_address(struct net_device *dev, void *p)
 {
 	struct sockaddr *addr = p;
@@ -1506,7 +1498,6 @@ static const struct file_operations atmel_proc_fops = {
 static const struct net_device_ops atmel_netdev_ops = {
 	.ndo_open 		= atmel_open,
 	.ndo_stop		= atmel_close,
-	.ndo_change_mtu 	= atmel_change_mtu,
 	.ndo_set_mac_address 	= atmel_set_mac_address,
 	.ndo_start_xmit 	= start_tx,
 	.ndo_do_ioctl 		= atmel_ioctl,
@@ -1600,6 +1591,10 @@ struct net_device *init_atmel_card(unsigned short irq, unsigned long port,
 	dev->irq = irq;
 	dev->base_addr = port;
 
+	/* MTU range: 68 - 2312 */
+	dev->min_mtu = 68;
+	dev->max_mtu = MAX_WIRELESS_BODY - ETH_FCS_LEN;
+
 	SET_NETDEV_DEV(dev, sys_dev);
 
 	if ((rc = request_irq(dev->irq, service_interrupt, IRQF_SHARED, dev->name, dev))) {