SDL2: Add missing symbol loading for SDL_GetDefaultAudioInfo() implementation on ALSA.

(cherry picked from commit 874ca5a678f9452b5f868290343f2a95f21ab5ac)

src/audio/alsa/SDL_alsa_audio.c

@@ -160,6 +160,7 @@ static int load_alsa_syms(void)
     SDL_ALSA_SYM(snd_pcm_avail);
     SDL_ALSA_SYM(snd_pcm_info);
     SDL_ALSA_SYM(snd_pcm_info_get_card);
+    SDL_ALSA_SYM(snd_pcm_info_get_name);
     SDL_ALSA_SYM(snd_card_get_name);
     SDL_ALSA_SYM(snd_pcm_info_malloc);
     SDL_ALSA_SYM(snd_pcm_info_free);