docs/system: Convert qemu-cpu-models.texi to rST

docs/system: Convert qemu-cpu-models.texi to rST

This doc was originally written by Daniel P. Berrangé
<berrange@redhat.com>, introduced via commit[1]: 2544e9e4aa (docs: add
guidance on configuring CPU models for x86, 2018-06-27).

In this patch:

  - 1-1 conversion of Texinfo to rST, besides a couple of minor
    tweaks that are too trivial to mention.   (Thanks to Stephen
    Finucane on IRC for the suggestion to use rST "definition lists"
    instead of bullets in some places.)

    Further modifications will be done via a separate patch.

  - rST and related infra changes: manual page generation, Makefile
    fixes, clean up references to qemu-cpu-models.texi, update year in
    the copyright notice, etc.

[1] https://git.qemu.org/?p=qemu.git;a=commit;h=2544e9e4aa

As part of the conversion, we use a more generic 'author' attribution
for the manpage than we previously had, as agreed with the original
author Dan Berrange.

Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200228153619.9906-16-peter.maydell@linaro.org
Message-id: 20200226113034.6741-15-pbonzini@redhat.com
[Move macros to defs.rst.inc, split in x86 and MIPS parts,
 make qemu-cpu-models.rst a standalone document. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[PMM: Move defs.rst.inc setup to its own commit;
 fix minor issues with MAINTAINERS file updates;
 drop copyright date change; keep capitalization of
 "QEMU Project developers" consistent with other uses;
 minor Makefile fixups]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>