add missing flags in sys/timerfd.h

include/sys/timerfd.h

@@ -6,6 +6,12 @@ extern "C" {
 #endif
 
 #include <time.h>
+#include <fcntl.h>
+
+#define TFD_NONBLOCK O_NONBLOCK
+#define TFD_CLOEXEC O_CLOEXEC
+
+#define TFD_TIMER_ABSTIME 1
 
 int timerfd_create(int, int);
 int timerfd_settime(int, int, const struct itimerspec *, struct itimerspec *);