Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.0-20200324' into staging

ppc patch queue for 2020-03-24

Here's a final pull request before the qemu-5.0 hard freeze.

We have an implementation of the POWER9 forms of the slbia
instruction, a small cleanup and a handful of assorted fixes.

# gpg: Signature made Tue 24 Mar 2020 05:12:30 GMT
# 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-5.0-20200324:
  ppc/ppc405_boards: Remove unnecessary NULL check
  hw/ppc: Take QEMU lock when calling ppc_dcr_read/write()
  spapr: Fix memory leak in h_client_architecture_support()
  target/ppc: don't byte swap ELFv2 signal handler
  target/ppc: Fix ISA v3.0 (POWER9) slbia implementation
  target/ppc: Fix slbia TLB invalidation gap
  ppc/spapr: Set the effective address provided flag in mc error log.

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