DolphinWX: fix input bitmaps not working when background input is off

Source/Core/DolphinWX/UINeedsControllerState.cpp

@@ -0,0 +1,17 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <atomic>
+
+static std::atomic<bool> s_needs_controller_state{false};
+
+void SetUINeedsControllerState(bool needs_controller_state)
+{
+  s_needs_controller_state = needs_controller_state;
+}
+
+bool GetUINeedsControllerState()
+{
+  return s_needs_controller_state;
+}