Get emulator rendering working with Qt

include/renderer_sw/renderer_sw.hpp

@@ -15,4 +15,8 @@ class RendererSw final : public Renderer {
 	void textureCopy(u32 inputAddr, u32 outputAddr, u32 totalBytes, u32 inputSize, u32 outputSize, u32 flags) override;
 	void drawVertices(PICA::PrimType primType, std::span<const PICA::Vertex> vertices) override;
 	void screenshot(const std::string& name) override;
+
+#ifdef PANDA3DS_FRONTEND_QT
+	virtual void initGraphicsContext([[maybe_unused]] GL::Context* context) override {}
+#endif
 };