fix bsd build

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@5223 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch.h

@@ -55,6 +55,9 @@
 #ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 600
 #endif
+#ifndef __BSD_VISIBLE
+#define __BSD_VISIBLE 1
+#endif
 #endif
 #include <stdlib.h>
 #include <stdio.h>