Ages ago we supported pxelinux. Now, not really since it is long EOL.
And while troubleshooting bug # 2033430, we discovered we had option
210 in the DHCP payload from the server, which ended up being the
folder base path for a tftp client to self reference the structure,
but only with OVN.
Further troubleshooting with the neutron-dhcp-agent and dnsmasq
revealed we never actaully really sent that option to clients.
In other words, meaning it was always redundant. Since excess
information could be part of the problem with grub, we're removing
it.
Change-Id: Iaa2f174b6082fadcab6635ca874fc5fae2fb4842
980611186e