staging: r8712u: Add new USB ID

Add USB ID for Sitecom WLA-2000 v1.001 WLAN.

Reported-and-tested-by: Roland Gruber <post@rolandgruber.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>