USB: serial: ftdi_sio: add device ID for WICED USB UART dev board

BCM20706V2_EVAL is a WICED dev board designed with FT2232H USB 2.0
UART/FIFO IC.

To support BCM920706V2_EVAL dev board for WICED development on Linux.
Add the VID(0a5c) and PID(6422) to ftdi_sio driver to allow loading
ftdi_sio for this board.

Signed-off-by: Sheng-Hui J. Chu <s.jeffrey.chu@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>