Fix compilation with --disable-everything --enable-demuxer=matroska.

Fixes ticket #3693.

libavcodec/Makefile

@@ -671,7 +671,8 @@ OBJS-$(CONFIG_ISMV_MUXER)              += mpeg4audio.o mpegaudiodata.o
 OBJS-$(CONFIG_LATM_MUXER)              += mpeg4audio.o
 OBJS-$(CONFIG_MATROSKA_AUDIO_MUXER)    += xiph.o mpeg4audio.o vorbis_data.o \
                                           flac.o flacdata.o
-OBJS-$(CONFIG_MATROSKA_DEMUXER)        += mpeg4audio.o mpegaudiodata.o
+OBJS-$(CONFIG_MATROSKA_DEMUXER)        += mpeg4audio.o mpegaudiodata.o \
+                                          vorbis_parser.o xiph.o
 OBJS-$(CONFIG_MATROSKA_MUXER)          += mpeg4audio.o mpegaudiodata.o  \
                                           flac.o flacdata.o vorbis_data.o xiph.o
 OBJS-$(CONFIG_MP2_MUXER)               += mpegaudiodata.o mpegaudiodecheader.o

libavformat/Makefile

@@ -205,7 +205,7 @@ OBJS-$(CONFIG_LXF_DEMUXER)               += lxfdec.o
 OBJS-$(CONFIG_M4V_DEMUXER)               += m4vdec.o rawdec.o
 OBJS-$(CONFIG_M4V_MUXER)                 += rawenc.o
 OBJS-$(CONFIG_MATROSKA_DEMUXER)          += matroskadec.o matroska.o  \
-                                            isom.o rmsipr.o \
+                                            isom.o rmsipr.o flac_picture.o \
                                             oggparsevorbis.o vorbiscomment.o
 OBJS-$(CONFIG_MATROSKA_MUXER)            += matroskaenc.o matroska.o \
                                             isom.o avc.o hevc.o \