Add Oceanic PID to ftdi_sio driver

Oceanic dive computers (such as the VT3 --
http://www.oceanicworldwide.com/p_computers_vt3.html) all use an onboard
FTDI serial converter, with the FTDI vid and a  PID of 0xf460.  The
attached patch adds that pid to ftdi_sio; driver  connects to my VT3
after that.
Signed-off-by: Vladimir Vukicevic <vladimir@pobox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>