Set GPU priorities + improved modeld priorities (#2691)

* give gpu threads rt priority

* modeld gets highest prio on core 2

* fix frame stream

* lower prio of cal thread

Co-authored-by: Comma Device <device@comma.ai>
old-commit-hash: c57ee16e86275820f97631fb79df1685e914d564

selfdrive/manager.py

@@ -233,6 +233,7 @@ car_started_processes = [
   'calibrationd',
   'paramsd',
   'camerad',
+  'modeld',
   'proclogd',
   'locationd',
   'clocksd',
@@ -263,9 +264,6 @@ if ANDROID:
     'rtshield',
   ]
 
-# starting dmonitoringmodeld when modeld is initializing can sometimes \
-# result in a weird snpe state where dmon constantly uses more cpu than normal.
-car_started_processes += ['modeld']
 
 def register_managed_process(name, desc, car_started=False):
   global managed_processes, car_started_processes, persistent_processes