staging: rtl8712: Add device ID for Sitecom WLA2100

commit 1e6e63283691a2a9048a35d9c6c59cf0abd342e4 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>