Add grains value for IPMI ip addresses

There are times when we need to be able to easily associate a host with its BMC controller. To make finding this information easier, we are looking to add a grain value to the kinetic framework to save this information. We need to account for this on both physical hardware and virtual machines. Examples are below, the physical host should report its IP address and mac address, for virtual hosts since we don't have access to this, so we just return nothing.

# salt \* grains.item ipmi


<physical-host>:
    ----------
    ipmi:
        ----------
        ipv4_address:
            172.16.2.32/22
        mac_address:
            0c:c4:7a:22:19:b6
        present:
            True

<virtual-host>:
    ----------
    ipmi: