staging: rtl8712: Add device ID for Sitecom WLA2100

This adds the USB ID for the Sitecom WLA2100. The Windows 10 inf file
was checked to verify that the addition is correct.
Reported-by: Frans van de Wiel <fvdw@fvdw.eu>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Frans van de Wiel <fvdw@fvdw.eu>
Cc: Stable <stable@vger.kernel.org> [All stable versions]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/usb_intf.c

@@ -144,6 +144,7 @@ static struct usb_device_id rtl871x_usb_id_tbl[] = {
 	{USB_DEVICE(0x0DF6, 0x0058)},
 	{USB_DEVICE(0x0DF6, 0x0049)},
 	{USB_DEVICE(0x0DF6, 0x004C)},
+	{USB_DEVICE(0x0DF6, 0x006C)},
 	{USB_DEVICE(0x0DF6, 0x0064)},
 	/* Skyworth */
 	{USB_DEVICE(0x14b2, 0x3300)},