[Skiboot] [PATCH 0/9] Initial "big cores" support for POWER9

[Benjamin Herrenschmidt]

This is based on initial work by Ryan Grimm with additions & cleanups by
myself.

Some notes:

 - This currently needs a special modified HostBoot

 - It's missing the "ibm,thread-groups" property to inform Linux about big cores

 - We need to look at HMI issues, as in some cases TFAC errors get only sent to
   one half but both half need to rendez-vous, so we need to "trigger" an error
   in the other half as well.

The above aren't blockers, it should be possible to merge this first.