renderer: expand rectangle lists with tessellation

Remove the legacy NGG rectangle workaround and its configuration toggle.

src/common/emulatorConfig.cpp

@@ -89,10 +89,6 @@ bool RenderDocEnabled() {
 	return g_config->renderdoc_enabled;
 }
 
-bool NggRectlistDrawEnabled() {
-	return g_config->ngg_rectlist_draw_enabled;
-}
-
 bool ReadbackLinearImagesEnabled() {
 	return g_config->readback_linear_images;
 }