USB: serial: cp210x: added Ketra N1 wireless interface support

Added support for Ketra N1 wireless interface, which uses the
Silicon Labs' CP2104 USB to UART bridge with customized PID 8946.
Signed-off-by: Joe Savage <joe.savage@goketra.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

(cherry picked from commit bfc2d7df)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

drivers/usb/serial/cp210x.c

@@ -122,6 +122,7 @@ static const struct usb_device_id id_table[] = {
 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
 	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
 	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
+	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */