Add two extra fields to struct mp3entry, in preparation for making ATRAC3 more generic. (i.e, to avoid having to pass it RMContext even when the codec has nothing to do with rm.)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24680 a1c6a512-1295-4272-9138-f99709370657

apps/metadata.h

@@ -227,6 +227,9 @@ struct mp3entry {
     bool has_toc;           /* True if there is a VBR header in the file */
     unsigned char toc[100]; /* table of contents */
 
+    /* Added for ATRAC3 */
+    unsigned int channels;       /* Number of channels in the stream */
+    unsigned int extradata_size; /* Size (in bytes) of the codec's extradata from the container */
     /* these following two fields are used for local buffering */
     char id3v2buf[ID3V2_BUF_SIZE];
     char id3v1buf[4][92];