Fixed iOS and Android build

src/render/opengles/SDL_render_gles.c

@@ -22,6 +22,7 @@
 
 #if SDL_VIDEO_RENDER_OGL_ES && !SDL_RENDER_DISABLED
 
+#include "SDL_assert.h"
 #include "SDL_hints.h"
 #include "SDL_opengles.h"
 #include "../SDL_sysrender.h"