Added missing includes

mem.c

@@ -25,8 +25,10 @@
  */
 
 #include <stddef.h>
+#include <exec/io.h>
 #include <exec/types.h>
 #include <exec/memory.h>
+#include <exec/semaphores.h>
 #include <clib/exec_protos.h>
 
 #include "ntimed.h"