Merge remote-tracking branch 'remotes/vivier/tags/q800-for-5.0-pull-request' into...

m68k: fix CACR valid bits
q800: add a fake mac rom reset (used by linux)
      fix and improve PRAM emulation

# gpg: Signature made Tue 07 Jan 2020 13:25:50 GMT
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier/tags/q800-for-5.0-pull-request:
  target/m68k: only change valid bits in CACR
  q800: implement mac rom reset function for BIOS-less mode
  q800: add a block backend to the PRAM
  q800: fix mac_via RTC PRAM commands

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