drivers/net/smc911x.c: Fix GCC 4.6 warning

smc911x.c: In function 'smc911x_initialize':
smc911x.c:288:12: warning: assignment from incompatible pointer type
[enabled by default]

Signed-off-by: Anatolij Gustschin <agust@denx.de>

drivers/net/smc911x.c

@@ -161,8 +161,7 @@ static int smc911x_init(struct eth_device *dev, bd_t * bd)
 	return 0;
 }
 
-static int smc911x_send(struct eth_device *dev,
-			volatile void *packet, int length)
+static int smc911x_send(struct eth_device *dev, void *packet, int length)
 {
 	u32 *data = (u32*)packet;
 	u32 tmplen;