wayland: Fix a circular include issue

The event header being included before a header guard was hiding a circular include issue.

src/video/wayland/SDL_waylanddatamanager.h

@@ -25,7 +25,6 @@
 #define SDL_waylanddatamanager_h_
 
 #include "SDL_waylandvideo.h"
-#include "SDL_waylandevents_c.h"
 #include "SDL_waylandwindow.h"
 
 #define TEXT_MIME            "text/plain;charset=utf-8"