[core] No need for default ctor in {Update,Tile}Parameters

include/mbgl/renderer/renderer.hpp

@@ -19,7 +19,7 @@ class RendererObserver;
 class RenderedQueryOptions;
 class Scheduler;
 class SourceQueryOptions;
-class UpdateParameters;
+struct UpdateParameters;
 class View;
 
 class Renderer {

include/mbgl/renderer/renderer_frontend.hpp

@@ -5,7 +5,7 @@
 namespace mbgl {
 
 class RendererObserver;
-class UpdateParameters;
+struct UpdateParameters;
 
 // The RenderFrontend is the bridge between the Map and
 // platform used to update and observer the Renderer