Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.1-20200507' into staging

ppc patch queue for 2020-04-07

First pull request for qemu-5.1.  This includes:
 * Removal of all remaining cases where we had CAS triggered reboots
 * A number of improvements to NMI injection
 * Support for partition scoped radix translation in softmmu
 * Some fixes for NVDIMM handling
 * A handful of other minor fixes

# gpg: Signature made Thu 07 May 2020 06:00:55 BST
# gpg:                using RSA key 75F46586AE61A66CC44E87DC6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>" [full]
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>" [full]
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>" [full]
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>" [unknown]
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-5.1-20200507:
  target-ppc: fix rlwimi, rlwinm, rlwnm for Clang-9
  spapr_nvdimm: Tweak error messages
  spapr_nvdimm.c: make 'label-size' mandatory
  target/ppc: Add support for Radix partition-scoped translation
  target/ppc: Rework ppc_radix64_walk_tree() for partition-scoped translation
  target/ppc: Extend ppc_radix64_check_prot() with a 'partition_scoped' bool
  target/ppc: Introduce ppc_radix64_xlate() for Radix tree translation
  spapr: Don't allow unplug of NVLink2 devices
  target/ppc: Assert if HV mode is set when running under a pseries machine
  target/ppc: Introduce a relocation bool in ppc_radix64_handle_mmu_fault()
  target/ppc: Enforce that the root page directory size must be at least 5
  spapr: Drop CAS reboot flag
  spapr/cas: Separate CAS handling from rebuilding the FDT
  spapr: Simplify selection of radix/hash during CAS
  ppc/pnv: Add support for NMI interface
  ppc/spapr: tweak change system reset helper
  spapr: Don't check capabilities removed between CAS calls
  target/ppc: Improve syscall exception logging

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>