staging: r8712u: Add new device ID

The ISY IWL 1000 USB WLAN stick with USB ID 050d:11f1 is a clone of
the Belkin F7D1101 V1 device.

Reported-by: Thomas Hartmann <hartmann@ict.tuwien.ac.at>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Thomas Hartmann <hartmann@ict.tuwien.ac.at>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>