fix win32 ms time fail

`GetSystemTimeAsFileTime` returns 100 nano seconds elapsed time,
not 100 micro seconds.

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/platform_util.c b/library/platform_util.c
index d8d9708..c784ea4 100644
--- a/library/platform_util.c
+++ b/library/platform_util.c
@@ -200,7 +200,7 @@
 
     GetSystemTimeAsFileTime(&ct);
     current_ms = ((mbedtls_ms_time_t) ct.dwLowDateTime +
-                  ((mbedtls_ms_time_t) (ct.dwHighDateTime) << 32LL))/10;
+                  ((mbedtls_ms_time_t) (ct.dwHighDateTime) << 32LL))/10000;
     return current_ms;
 }
 #else