Add dependencies used by the RDT and ASF/RTP code

Originally committed as revision 22538 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1372,6 +1372,7 @@ rtsp_demuxer_deps="sdp_demuxer"
 rtsp_muxer_deps="sdp_demuxer"
 rtsp_muxer_select="rtp_muxer"
 sdp_demuxer_deps="rtp_protocol mpegts_demuxer"
+sdp_demuxer_select="asf_demuxer rm_demuxer"
 spdif_muxer_select="aac_parser"
 tg2_muxer_select="mov_muxer"
 tgp_muxer_select="mov_muxer"