id3lib: fix autoheader warning due to missing AC_DEFINE template

For more information:
https://www.mail-archive.com/openembedded-devel@lists.openembedded.org/msg36641.html



Signed-off-by: Matthieu Crapet <Matthieu.Crapet@ingenico.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>