video_core; Get rid of global g_toggle_framelimit_enabled variable

Instead, we make a struct for renderer settings and allow the renderer
to update all of these settings, getting rid of the need for
global-scoped variables.

This also uncovered a few indirect inclusions for certain headers, which
this commit also fixes.

src/video_core/video_core.h

@@ -4,7 +4,6 @@
 
 #pragma once
 
-#include <atomic>
 #include <memory>
 
 class EmuWindow;
@@ -13,10 +12,6 @@ namespace VideoCore {
 
 class RendererBase;
 
-// TODO: Wrap these in a user settings struct along with any other graphics settings (often set from
-// qt ui)
-extern std::atomic<bool> g_toggle_framelimit_enabled;
-
 /**
  * Creates a renderer instance.
  *