MAINTAINERS: new maintainers for QOM

MAINTAINERS: new maintainers for QOM

QOM is not a particularly active subsystem now: 51 commits in two years.
But, we need active maintainers to review and merge patches, and Git
shows the following top committers taking on QOM:

    Markus Armbruster <armbru@redhat.com>
    Eduardo Habkost <ehabkost@redhat.com>
    Paolo Bonzini <pbonzini@redhat.com>
    Marc-André Lureau <marcandre.lureau@redhat.com>
    Eric Blake <eblake@redhat.com>

I volunteer myself, and also volunteer Eduardo and Daniel as reviewers
since they understand the code well.

Cc: Andreas Färber <afaerber@suse.de>
Cc: Daniel P. Berrange <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190619201050.19040-2-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Andreas Färber <afaerber@suse.de>