USB: ftdi-sio: add support for Physik Instrumente E-861

This adds VID/PID for the PI E-861. Without it, I had to do:
modprobe -q ftdi-sio product=0x1008 vendor=0x1a72

http://www.physikinstrumente.com/en/products/prdetail.php?sortnr=900610



Signed-off-by: Éric Piel <piel@delmic.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>