UIO: Add a driver for Hilscher netX-based fieldbus cards

This patch adds a Userspace IO driver for netX-based fieldbus cards by
Hilscher (see http://www.hilscher.com). ATM, cifX and comX cards are
supported. The userspace part for this driver is provided by Hilscher
and should come with the card.
The driver is in use for several months now and has been tested by
people at Hilscher and Linutronix.

Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>