avformat/Makefile: Remove outdated AIFF demuxer dependency on iso_media

This is a result of the mov channel parsing stuff being factored out
of mov.c twice: Once in 91b782720f
to isom.c and later in 3bab7cd128.

Also remove the isom.h header; and while just at it, remove an unused
mathematics.h inclusion.

(isom.c actually depends upon mpeg4audio from libavcodec for
avpriv_mpeg4audio_get_config2 and avpriv_mpa_freq_tab; yet there is
no configure dependency for iso_media which leads to failure of shared
builds.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/Makefile

@@ -81,7 +81,7 @@ OBJS-$(CONFIG_ADX_DEMUXER)               += adxdec.o
 OBJS-$(CONFIG_ADX_MUXER)                 += rawenc.o
 OBJS-$(CONFIG_AEA_DEMUXER)               += aea.o pcm.o
 OBJS-$(CONFIG_AFC_DEMUXER)               += afc.o
-OBJS-$(CONFIG_AIFF_DEMUXER)              += aiffdec.o pcm.o isom.o \
+OBJS-$(CONFIG_AIFF_DEMUXER)              += aiffdec.o pcm.o \
                                             mov_chan.o replaygain.o
 OBJS-$(CONFIG_AIFF_MUXER)                += aiffenc.o id3v2enc.o
 OBJS-$(CONFIG_AIX_DEMUXER)               += aixdec.o

libavformat/aiffdec.c

@@ -20,13 +20,11 @@
  */
 
 #include "libavutil/intreadwrite.h"
-#include "libavutil/mathematics.h"
 #include "libavutil/dict.h"
 #include "avformat.h"
 #include "internal.h"
 #include "pcm.h"
 #include "aiff.h"
-#include "isom.h"
 #include "id3v2.h"
 #include "mov_chan.h"
 #include "replaygain.h"