Staging: comedi: add pcl821 driver

hardware driver for Advantech cards:
	PCL-812, PCL-812PG, PCL-813, PCL-813B
and for ADlink cards:
	ACL-8112DG, ACL-8112HG, ACL-8112PG, ACL-8113, ACL-8216
and for ICP DAS cards:
	ISO-813, A-821PGH, A-821PGL, A-821PGL-NDA, A-822PGH, A-822PGL,
	A-823PGH, A-823PGL, A-826PG

From: Michal Dobes <dobes@tesnet.cz>
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>