staging: fieldbus: support HMS Profinet IRT industrial controller

staging: fieldbus: support HMS Profinet IRT industrial controller

The Anybus-S PROFINET IRT communication module provides instant integration
to any Ethernet based LAN via SMTP, FTP, HTTP as well as PROFINET and
Modbus-TCP. Additional protocols can be implemented on top of TCP/IP
or UDP using the transparent socket interface.

Official documentation:
https://www.anybus.com/docs/librariesprovider7/default-document-library
/manuals-design-guides/hms-hmsi-168-52.pdf

This implementation is an Anybus-S client driver, designed to be
instantiated by the Anybus-S bus driver when it discovers the Profinet
card.

If loaded successfully, the driver registers itself as a fieldbus_dev,
and userspace can access it through the fieldbus_dev interface.

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