Add required header #include to fix 'make checkheaders'.

Originally committed as revision 20612 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpegaudio_tablegen.h

@@ -27,6 +27,7 @@
 // do not use libavutil/mathematics.h since this is compiled both
 // for the host and the target and config.h is only valid for the target
 #include <math.h>
+#include "config.h"
 
 #define TABLE_4_3_SIZE (8191 + 16)*4
 #if CONFIG_HARDCODED_TABLES