Pull powerpc fixes from Michael Ellerman:
 - Fixup preempt underflow with huge pages from Sebastian Siewior
 - Fix altivec SPR not being saved from Oliver O'Halloran
 - Correct used_vsr comment from Simon Guo

* tag 'powerpc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc: Correct used_vsr comment
  powerpc/process: Fix altivec SPR not being saved
  powerpc/mm: Fixup preempt underflow with huge pages