Fix static build with libdecor 0.2.0

(cherry picked from commit 4ce935b9106a0311436e41c5f28f00db30a93de1)

src/video/wayland/SDL_waylandsym.h

@@ -219,10 +219,10 @@ SDL_WAYLAND_SYM(int, libdecor_dispatch, (struct libdecor *, int))
 
 #if defined(SDL_VIDEO_DRIVER_WAYLAND_DYNAMIC_LIBDECOR) || defined(SDL_HAVE_LIBDECOR_GET_MIN_MAX)
 /* Only found in libdecor 0.1.1 or higher, so failure to load them is not fatal. */
-SDL_WAYLAND_SYM_OPT(void, libdecor_frame_get_min_content_size, (struct libdecor_frame *,\
+SDL_WAYLAND_SYM_OPT(void, libdecor_frame_get_min_content_size, (const struct libdecor_frame *,\
                                                             int *,\
                                                             int *))
-SDL_WAYLAND_SYM_OPT(void, libdecor_frame_get_max_content_size, (struct libdecor_frame *,\
+SDL_WAYLAND_SYM_OPT(void, libdecor_frame_get_max_content_size, (const struct libdecor_frame *,\
                                                             int *,\
                                                             int *))
 #endif