Fix compilation on Mac OS X, patch by Marc Hoffman, mmh pleasantst com.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@8067 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/rtsp.c

@@ -20,6 +20,7 @@
  */
 #include "avformat.h"
 
+#include <sys/time.h>
 #include <unistd.h> /* for select() prototype */
 #include "network.h"