Added CLOCKS_PER_SEC.

diff --git a/include/msvcrt/time.h b/include/msvcrt/time.h
index dc9a743..4b8b0af 100644
--- a/include/msvcrt/time.h
+++ b/include/msvcrt/time.h
@@ -59,6 +59,10 @@
 #endif
 #endif
 
+#ifndef CLOCKS_PER_SEC
+#define CLOCKS_PER_SEC 1000
+#endif
+
 #ifndef MSVCRT_TM_DEFINED
 #define MSVCRT_TM_DEFINED
 struct MSVCRT(tm) {