add parameter for logfile names to base::syslogs

so we can also use it for other files besides
/var/log/syslog and /var/log/messages, such as
/var/log/ocg.log needed by OCG

(also see Change-Id: I20f39776597837)

Change-Id: I5e4efa223b6caf235f3e94424d42c0f00192944d