Add accessor function to the uclock of an IOMux

src/iomux_impl.c

@@ -139,6 +139,11 @@ int iomux_update_events(struct IOMux *mux, struct IOMuxFD *fd)
     return mux->update_events_impl(mux, fd);
 }
 
+struct UCoreClock *iomux_get_clock(struct IOMux *mux)
+{
+    return mux->uclock;
+}
+
 struct UCTimers *iomux_get_timers(struct IOMux *mux)
 {
     return &mux->timers;