Fix headers so that "make checkheaders" passes again

Originally committed as revision 25411 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/amr.h

@@ -23,6 +23,8 @@
 #ifndef AVCODEC_AMR_H
 #define AVCODEC_AMR_H
 
+#include "avcodec.h"
+
 #ifdef AMR_USE_16BIT_TABLES
 #define R_TABLE_TYPE uint16_t
 #else

libavcodec/msgsmdec.h

@@ -22,6 +22,8 @@
 #ifndef MSGSMDEC_H
 #define MSGSMDEC_H
 
+#include "avcodec.h"
+
 int ff_msgsm_decode_block(AVCodecContext *avctx, int16_t *samples,
                           const uint8_t *buf);