make locationd and paramsd RT (#21264)

selfdrive/locationd/locationd.cc

@@ -469,7 +469,7 @@ int Localizer::locationd_thread() {
 }
 
 int main() {
-  setpriority(PRIO_PROCESS, 0, -20);
+  set_realtime_priority(5);
 
   Localizer localizer;
   return localizer.locationd_thread();

selfdrive/locationd/paramsd.py

@@ -8,7 +8,7 @@ import numpy as np
 import cereal.messaging as messaging
 from cereal import car
 from common.params import Params, put_nonblocking
-from common.realtime import DT_MDL
+from common.realtime import set_realtime_priority, DT_MDL
 from common.numpy_fast import clip
 from selfdrive.locationd.models.car_kf import CarKalman, ObservationKind, States
 from selfdrive.locationd.models.constants import GENERATED_DIR
@@ -73,6 +73,7 @@ class ParamsLearner:
 
 def main(sm=None, pm=None):
   gc.disable()
+  set_realtime_priority(5)
 
   if sm is None:
     sm = messaging.SubMaster(['liveLocationKalman', 'carState'], poll=['liveLocationKalman'])