Expose syslog parameters: use_syslog and log_facility

Both parameters defaults to the openstack modules default values:
  - use_syslog: false
  - log_facility: LOG_USER

Change-Id: I8d67027791b1e212aa5ab129b9d49e939b9e5203
Merge "Expose syslog parameters: use_syslog and log_facility"