vlan: Pass SIOC[SG]HWTSTAMP ioctls to real device

This allows applications to enable hardware timestamping without being aware
of it being a vlan device and figuring out the real device.
Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan_dev.c

@@ -385,6 +385,8 @@ static int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 	case SIOCGMIIPHY:
 	case SIOCGMIIREG:
 	case SIOCSMIIREG:
+	case SIOCSHWTSTAMP:
+	case SIOCGHWTSTAMP:
 		if (netif_device_present(real_dev) && ops->ndo_do_ioctl)
 			err = ops->ndo_do_ioctl(real_dev, &ifrr, cmd);
 		break;