The remaining text in docs/barrier.txt is user-facing description
of what the device is and how to use it. Move this into the
system manual and rstify it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210727204112.12579-4-peter.maydell@linaro.org
