Enable direct submit optimization in audio and video decoders

src/audio/alsa.c

@@ -101,4 +101,5 @@ AUDIO_RENDERER_CALLBACKS audio_callbacks_alsa = {
   .init = alsa_renderer_init,
   .cleanup = alsa_renderer_cleanup,
   .decodeAndPlaySample = alsa_renderer_decode_and_play_sample,
+  .capabilities = CAPABILITY_DIRECT_SUBMIT,
 };

src/audio/sdl.c

@@ -76,4 +76,5 @@ AUDIO_RENDERER_CALLBACKS audio_callbacks_sdl = {
   .init = sdl_renderer_init,
   .cleanup = sdl_renderer_cleanup,
   .decodeAndPlaySample = sdl_renderer_decode_and_play_sample,
+  .capabilities = CAPABILITY_DIRECT_SUBMIT,
 };