ppc patch queue 2018-03-06 This pull request supersedes ppc-for-2.12-20180302 which had compile problems with some gcc versions. It also contains a few additional patches. Highlights are: * New Sam460ex machine type * Yet more fixes related to vcpu id allocation for spapr * Numerous macio cleanupsr * Some enhancements to the Spectre/Meltdown fixes for pseries, allowing use of a better mitigation for indirect branch based exploits * New pseries machine types with Spectre/Meltdown mitigations enabled (stop gap until libvirt and management understands the machine options) * A handful of other fixes