cmake: Weak link to GameController.framework to handle older OSes

CMakeLists.txt

@@ -2055,7 +2055,9 @@ elseif(APPLE)
   endif()
   if(SDL_FRAMEWORK_GAMECONTROLLER)
     find_library(GAMECONTROLLER GameController)
-    list(APPEND EXTRA_LIBS ${GAMECONTROLLER})
+    if(GAMECONTROLLER)
+      list(APPEND EXTRA_LDFLAGS "-Wl,-weak_framework,GameController")
+    endif()
   endif()
   if(SDL_FRAMEWORK_METAL)
     if(IOS OR TVOS)