i40e should only register ufm data on func 0
Today, i40e reports a UFM entry on all of its instances. However, the UFM it represents is device wide and in fact it is shared between all ports on the device. Instead we should only report UFM data if this is function zero of the device. Otherwise, this gives the illusion in fwflash and topo that they each of the functions (which should up as different instances) have independent UFMs. However, changing one actually changes them all.