[Skiboot] OpenPower gard tool rework

[Stewart Smith]

Oliver O'Halloran <oohall at gmail.com> writes:
> This series contains a substantial rework of the OpenPower gard tool.
> The main additions being:
>
> 	a) The ability to create GARD records
> 	b) Support for Power 9
> 	c) Support for running on ARM (i.e BMCs)
> 	d) Nicer output for the list subcommand.
> 	e) A basic understanding of where to find GUARD on OpenBMC
>            with vPNOR.
>
> This also does substantial (but incomplete) reworks of the internals of the
> tool to make it a bit easier to work with.
>
> Record creation has only been lightly tested, but it seems to work
> provided the user targets a hardware unit that actually exists which
> is good enough for me.

So, I think this is in a good enough state to merge into master, so I
have, as of e947593a38a15d4e80a108ae90a8fa9066d20837.

Before I tag the next release though, I'd like us to not have to require
the -8 or -9 flag, as well as have an API option that isn't just
directly poking at FFS and the GUARD partition.

-- 
Stewart Smith
OPAL Architect, IBM.