Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.12-20180410' into staging

ppc patch queue 2018-04-10

Here's a rather late pull request with a handful of fixes for 2.12.
These have been blocked for some time, because I wasn't able to
complete my usual test set due to the SCSI problem fixed in 37c51741
"scsi-disk: Don't enlarge min_io_size to max_io_size".

Since we're in hard freeze, these are all bugfixes.  Most are also
regressions, although in one case it's only a "regression" because a
longstanding bug has been exposed by a new machine type (sam460ex) in
the testcases.  There are also a couple of sam460ex fixes that aren't
regressions since the board didn't exist before.  On the flipside
though, they're low risk because they only touch board specific code
for a board that doesn't exist in any released version.

# gpg: Signature made Tue 10 Apr 2018 08:13:52 BST
# gpg:                using RSA key 6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.12-20180410:
  roms/u-boot-sam460ex: Change to qemu git mirror and update
  sam460ex: Fix timer frequency and clock multipliers
  tests/boot-serial: Test the sam460ex board
  spapr: Initialize reserved areas list in FDT in H_CAS handler
  target/ppc: Fix backwards migration of msr_mask
  hw/misc/macio: Fix crash when listing device properties of macio device
  target/ppc: Initialize lazy_tlb_flush correctly

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