Merge remote-tracking branch 'remotes/cohuck/tags/s390x-20200403' into staging

- fix cpu number reporting in the stsi 3.2.2 block for kvm
- fix migration for old machines with odd ram sizes

# gpg: Signature made Fri 03 Apr 2020 10:11:06 BST
# gpg:                using RSA key C3D0D66DC3624FF6A8C018CEDECF6B93C6F02FAF
# gpg:                issuer "cohuck@redhat.com"
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>" [marginal]
# gpg:                 aka "Cornelia Huck <huckc@linux.vnet.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cohuck@kernel.org>" [marginal]
# gpg:                 aka "Cornelia Huck <cohuck@redhat.com>" [marginal]
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* remotes/cohuck/tags/s390x-20200403:
  vl/s390x: fixup ram sizes for compat machines
  s390x: kvm: Fix number of cpu reports for stsi 3.2.2

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