Sync PNF through the radio

The radio gives the clock. Therefore, we do not need to keep the time
separately in the PNF.

Also, the VNF should not run the ru_thread, as this is an L1 thread.

executables/nr-ru.c

@@ -1216,29 +1216,7 @@ void *ru_thread(void *param)
   struct timespec slot_start;
 	clock_gettime(CLOCK_MONOTONIC, &slot_start);
   
-  struct timespec slot_duration; 
-	slot_duration.tv_sec = 0;
-	//slot_duration.tv_nsec = 0.5e6;
-	slot_duration.tv_nsec = 0.5e6;
-
-  
-
   while (!oai_exit) {
-    
-    if (NFAPI_MODE==NFAPI_MODE_VNF || NFAPI_MODE == NFAPI_MODE_AERIAL ) {
-      // We should make a VNF main loop with proper tasks calls in case of VNF
-      slot_start = timespec_add(slot_start,slot_duration);
-      struct timespec curr_time;
-      clock_gettime(CLOCK_MONOTONIC, &curr_time);    
-      struct timespec sleep_time;
-      
-      if((slot_start.tv_sec > curr_time.tv_sec) ||
-	 (slot_start.tv_sec == curr_time.tv_sec && slot_start.tv_nsec > curr_time.tv_nsec)){
-	sleep_time = timespec_sub(slot_start,curr_time);
-	usleep(sleep_time.tv_nsec * 1e-3); 
-      }
-    }
-    
     if (slot==(fp->slots_per_frame-1)) {
       slot=0;
       frame++;