Remove I_MIDIPlaying from other targets

src/android/i_sound.c

@@ -74,11 +74,6 @@ void I_ResumeSong(INT32 handle)
         (void)handle;
 }
 
-boolean I_MIDIPlaying(void)
-{
-	return false;
-}
-
 boolean I_MusicPlaying(void)
 {
 	return false;

src/djgppdos/i_sound.c

@@ -567,11 +567,6 @@ UINT32 I_GetMusicPosition(void)
     return 0;
 }
 
-boolean I_MIDIPlaying(void)
-{
-	return (boolean)currsong && music_started;
-}
-
 boolean I_MusicPlaying(void)
 {
 	return (boolean)currsong && music_started;

src/dummy/i_sound.c

@@ -162,11 +162,6 @@ UINT32 I_GetMusicPosition(void)
     return 0;
 }
 
-boolean I_MIDIPlaying(void)
-{
-	return false;
-}
-
 boolean I_MusicPlaying(void)
 {
 	return false;

src/sdl/sdl_sound.c

@@ -1649,12 +1649,6 @@ void I_StopSong(INT32 handle)
 #endif
 }
 
-boolean I_MIDIPlaying(void)
-{
-	// todo: no way to tell specifically if MIDI is playing, implement midimode
-	return !nomidimusic && nodigimusic && musicStarted;
-}
-
 boolean I_MusicPlaying(void)
 {
 	return musicStarted;

src/win32/win_snd.c

@@ -468,11 +468,6 @@ void I_ResumeSong(INT32 handle)
 		FMR_MUSIC(FMOD_Channel_SetPaused(music_channel, false));
 }
 
-boolean I_MIDIPlaying(void)
-{
-	return midimode && music_stream;
-}
-
 boolean I_MusicPlaying(void)
 {
 	return (boolean)music_stream;