807420f0b0
The system_clock_scale global is used only by the armv7m systick device; move the extern declaration to the armv7m_systick.h header, and expand the comment to explain what it is and that it should ideally be replaced with a different approach. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190516163857.6430-2-peter.maydell@linaro.org