Mellanox OpenIPMI repository.

This repo contains the following folders/files:
1) mlx-OpenIPMI-2.0.25 which is based on opensource OpenIPMI-2.0.25 with the following additions: 
    - Add support to the IPMB protocol and channel
    - Add mellanox-bf specific directory containing:
        - the service collecting sensors/FRUs data
        - the service running the ipmi_sim program
        - sdr.30 file
        - mlx-bf.lan.conf file
        - mlx-bf.emu file
        - prog.conf configuration file for enabling support to IPMB
     - debian folder for Ubuntu and debian builds
2) mlx-OpenIPMI.spec file for CentOS builds
3) mlx-OpenIPMI-2.0.25.tar.gz

Motivations behind creating a github repo instead of keeping a patch within BlueField's local repo:
1) Facilitate the build for various linux distributions
2) Facilitate sharing this code with customers
3) Avoid redundant use of a Mellanox OpenIPMI patch file

