Fix a compile problem on FreeBSD for a missing header.

In this specific case the problem triggered on app_amd.c,
but it keeps coming out from time to time so it is better
to fix it in a more central place.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@14320 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/compat.h

@@ -84,6 +84,10 @@ int unsetenv(const char *name);
 #define HAVE_STRNLEN
 #endif
 
+#ifdef __FreeBSD__
+#include <sys/types.h>
+#endif
+
 #ifdef SOLARIS
 #undef HAVE_VASPRINTF
 #undef HAVE_STRTOQ