Merge remote-tracking branch 'remotes/armbru/tags/pull-pflash-2019-03-11' into staging

Pflash and firmware configuration patches for 2019-03-11

# gpg: Signature made Mon 11 Mar 2019 21:59:12 GMT
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-pflash-2019-03-11: (27 commits)
  docs/interop/firmware.json: Prefer -machine to if=pflash
  pc: Support firmware configuration with -blockdev
  pc_sysfw: Pass PCMachineState to pc_system_firmware_init()
  pc_sysfw: Remove unused PcSysFwDevice
  pflash_cfi01: Add pflash_cfi01_get_blk() helper
  vl: Create block backends before setting machine properties
  vl: Factor configure_blockdev() out of main()
  vl: Improve legibility of BlockdevOptions queue
  sysbus: Fix latent bug with onboard devices
  vl: Fix latent bug with -global and onboard devices
  qom: Move compat_props machinery from qdev to QOM
  qdev: Fix latent bug with compat_props and onboard devices
  pflash: Clean up after commit 368a354f02b, part 2
  pflash: Clean up after commit 368a354f02b, part 1
  mips_malta: Clean up definition of flash memory size somewhat
  hw/mips/malta: Restrict 'bios_size' variable scope
  hw/mips/malta: Remove fl_sectors variable
  mips_malta: Delete disabled, broken DEBUG_BOARD_INIT code
  r2d: Fix flash memory size, sector size, width, device ID
  ppc405_boards: Don't size flash memory to match backing image
  ...

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