Replace NULL macro defs with null.h include

include/time.h

@@ -9,14 +9,14 @@
 #ifndef _TIME_H
 #define _TIME_H
 
+#include <sys/null.h>
+
 #define CLOCKS_PER_SEC    60
 
 #ifdef _POSIX_SOURCE
 #define CLK_TCK CLOCKS_PER_SEC	/* obsolescent mame for CLOCKS_PER_SEC */
 #endif
 
-#define NULL    ((void *)0)
-
 #ifndef _SIZE_T
 #define _SIZE_T
 typedef unsigned int size_t;