Staging: comedi: add aio_aio12_8 driver

Diver for Acces I/O Products PC-104 AIO12-8 Analog I/O Board

From: Pablo Mejia <pablo.mejia@cctechnol.com>
Cc: David Schleef <ds@schleef.org>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>