[201811][fancontrol] Restart process upon unexpected exit (#4161)

* Add restart configuration of fancontrol for pmon.

* Clean up the default value setting for exitcodes

* Remove the default setting of stopwaitsecs

dockers/docker-platform-monitor/supervisord.conf

@@ -33,9 +33,10 @@ startsecs=0
 command=/usr/sbin/fancontrol
 priority=4
 autostart=false
-autorestart=false
+autorestart=unexpected
 stdout_logfile=syslog
 stderr_logfile=syslog
+startsecs=10
 
 [program:ledd]
 command=/usr/bin/ledd