USB: serial: cp210x: add ID for GW Instek GDM-834x Digital Multimeter

Add the USB serial device ID for the GW Instek GDM-834x Digital Multimeter.

Signed-off-by: Uwe Brandt <uwe.brandt@gmail.com>
Link: https://lore.kernel.org/r/YUxFl3YUCPGJZd8Y@hovoldconsulting.com
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>