staging: fieldbus: anybus-s: support the Arcx anybus controller

Add a driver for the Arcx anybus controller.

This device implements two Anybus-S hosts (buses),
and connects to the SoC via a parallel memory bus.
There is also a CAN power readout, unrelated to the Anybus,
modelled as a regulator.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>