Core: Remove unnecessary includes

Also moves a cpp file's related header file to the top of the inclusions if it isn't already there.

Source/Core/Core/Config/Config.cpp

@@ -2,10 +2,10 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
-#include <tuple>
-
 #include "Core/Config/Config.h"
 
+#include <tuple>
+
 namespace Config
 {
 bool ConfigLocation::operator==(const ConfigLocation& other) const

Source/Core/Core/Config/GraphicsSettings.cpp

@@ -2,10 +2,11 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#include "Core/Config/GraphicsSettings.h"
+
 #include <string>
 
 #include "Core/Config/Config.h"
-#include "Core/Config/GraphicsSettings.h"
 #include "VideoCommon/VideoConfig.h"
 
 namespace Config