USB: serial: ftdi_sio: adding support for TavIR STK500

Adding support for the TavIR STK500 (id 0403:FA33)
Atmel AVR programmer device based on FTDI FT232RL.

Signed-off-by: Benedek László <benedekl@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>