AbstractTexture: Add missing includes (and remove unnecessary ones)

Source/Core/VideoCommon/AbstractTexture.h

@@ -4,10 +4,12 @@
 
 #pragma once
 
+#include <cstddef>
+#include <string>
+
 #include "Common/CommonTypes.h"
 #include "Common/MathUtil.h"
 #include "VideoCommon/TextureConfig.h"
-#include "VideoCommon/VideoCommon.h"
 
 class AbstractTexture
 {