build: Make the ISMV muxer select the MOV muxer

They share the same code, so building one w/o the other makes no sense.

configure

@@ -1646,6 +1646,7 @@ dirac_demuxer_select="dirac_parser"
 eac3_demuxer_select="ac3_parser"
 flac_demuxer_select="flac_parser"
 ipod_muxer_select="mov_muxer"
+ismv_muxer_select="mov_muxer"
 matroska_audio_muxer_select="matroska_muxer"
 matroska_demuxer_suggest="bzlib lzo zlib"
 mov_demuxer_suggest="zlib"

libavformat/Makefile

@@ -122,9 +122,6 @@ OBJS-$(CONFIG_IMAGE2PIPE_DEMUXER)        += img2dec.o img2.o
 OBJS-$(CONFIG_IMAGE2PIPE_MUXER)          += img2enc.o img2.o
 OBJS-$(CONFIG_INGENIENT_DEMUXER)         += ingenientdec.o rawdec.o
 OBJS-$(CONFIG_IPMOVIE_DEMUXER)           += ipmovie.o
-OBJS-$(CONFIG_ISMV_MUXER)                += movenc.o isom.o avc.o       \
-                                            movenchint.o rtpenc_chain.o \
-                                            mov_chan.o
 OBJS-$(CONFIG_ISS_DEMUXER)               += iss.o
 OBJS-$(CONFIG_IV8_DEMUXER)               += iv8.o
 OBJS-$(CONFIG_IVF_DEMUXER)               += ivfdec.o