Expose Renderer's Framecount

We don't want to move it, because we want to complete
this refactor without changing savestate version

Source/Core/VideoCommon/TextureCacheBase.cpp

@@ -783,7 +783,7 @@ void TextureCacheBase::OnFrameEnd()
     g_texture_cache->FlushEFBCopies();
   }
 
-  g_texture_cache->Cleanup(g_renderer->m_frame_count);
+  g_texture_cache->Cleanup(g_renderer->FrameCount());
 }
 
 void TCacheEntry::DoState(PointerWrap& p)