Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.0-20200203' into staging

ppc patch queue 2020-02093

This pull request supersedes ppc-for-5.0-20200131.  The only changes
are one extra patch to suppress some irritating warnings during tests
under TCG, and an extra Tested-by in one of the other patches.

Here's the next batch of patches for ppc and associated machine types.
Highlights includes:
 * Remove the deprecated "prep" machine type and its OpenHackware
   firmware
 * Add TCG emulation of the msgsndp etc. supervisor privileged
   doorbell instructions
 * Allow "pnv" machine type to run Hostboot style firmwares
 * Add a virtual TPM device for spapr machines
 * Implement devices for POWER8 PHB3 and POWER9 PHB4 host bridges for
   the pnv machine type
 * Use faster Spectre mitigation by default for POWER9 DD2.3 machines
 * Introduce Firmware Assisted NMI dump facility for spapr machines
 * Fix a performance regression with load/store multiple instructions
   in TCG

as well as some other assorted cleanups and fixes.

# gpg: Signature made Mon 03 Feb 2020 03:30:24 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-5.0-20200203: (35 commits)
  tests: Silence various warnings with pseries
  target/ppc: Use probe_write for DCBZ
  target/ppc: Remove redundant mask in DCBZ
  target/ppc: Use probe_access for LMW, STMW
  target/ppc: Use probe_access for LSW, STSW
  ppc: spapr: Activate the FWNMI functionality
  migration: Include migration support for machine check handling
  ppc: spapr: Handle "ibm,nmi-register" and "ibm,nmi-interlock" RTAS calls
  target/ppc: Build rtas error log upon an MCE
  target/ppc: Handle NMI guest exit
  ppc: spapr: Introduce FWNMI capability
  Wrapper function to wait on condition for the main loop mutex
  target/ppc/cpu.h: Put macro parameter in parentheses
  spapr: Enable DD2.3 accelerated count cache flush in pseries-5.0 machine
  ppc/pnv: change the PowerNV machine devices to be non user creatable
  ppc/pnv: Add models for POWER8 PHB3 PCIe Host bridge
  ppc/pnv: Add models for POWER9 PHB4 PCIe Host bridge
  docs/specs/tpm: reST-ify TPM documentation
  hw/ppc/Kconfig: Enable TPM_SPAPR as part of PSERIES config
  tpm_spapr: Support suspend and resume
  ...

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