audio_format: remove the reverse_endian attribute

Eliminate support for reverse endian samples from the MPD core.  This
moves a lot of complexity to the plugins that really need it (only
ALSA and CDIO currently).

src/filter/convert_filter_plugin.c

@@ -141,7 +141,6 @@ convert_filter_set(struct filter *_filter,
 	assert(audio_format_valid(&filter->out_audio_format));
 	assert(out_audio_format != NULL);
 	assert(audio_format_valid(out_audio_format));
-	assert(!filter->in_audio_format.reverse_endian);
 
 	filter->out_audio_format = *out_audio_format;
 }

src/filter/normalize_filter_plugin.c

@@ -67,7 +67,6 @@ normalize_filter_open(struct filter *_filter,
 	struct normalize_filter *filter = (struct normalize_filter *)_filter;
 
 	audio_format->format = SAMPLE_FORMAT_S16;
-	audio_format->reverse_endian = false;
 
 	filter->compressor = Compressor_new(0);
 

src/filter/replay_gain_filter_plugin.c

@@ -140,8 +140,6 @@ replay_gain_filter_open(struct filter *_filter,
 	struct replay_gain_filter *filter =
 		(struct replay_gain_filter *)_filter;
 
-	audio_format->reverse_endian = false;
-
 	filter->audio_format = *audio_format;
 	pcm_buffer_init(&filter->buffer);
 

src/filter/volume_filter_plugin.c

@@ -74,8 +74,6 @@ volume_filter_open(struct filter *_filter, struct audio_format *audio_format,
 {
 	struct volume_filter *filter = (struct volume_filter *)_filter;
 
-	audio_format->reverse_endian = false;
-
 	filter->audio_format = *audio_format;
 	pcm_buffer_init(&filter->buffer);