Make the interval an option

clock-res/src/clockres.c

@@ -103,7 +103,7 @@ static void *timerthread(void *p) {
     stat->max_res = max(stat->max_res, diff);
     stat->min_res = min(stat->min_res, diff);
 
-    next.tv_nsec += 10000000;
+    next.tv_nsec += param->interval;
 
     if(next.tv_nsec >= NSEC_PER_SEC) {
       next.tv_sec += 1;