Add posibility to configure logfile param

Change-Id: Iac37132f89dab9b489b864070022c5ddc926d006
diff --git a/metadata/service/client/single.yml b/metadata/service/client/single.yml
index f0d44e1..c6f6e8b 100644
--- a/metadata/service/client/single.yml
+++ b/metadata/service/client/single.yml
@@ -9,6 +9,7 @@
   ntp:
     client:
       enabled: true
+      logfile: '/var/log/ntp.log'
       stratum:
         primary:
           server: ${_param:ntp_strata_host1}
@@ -16,3 +17,4 @@
     server:
       enabled: false
       mode7: false
+      logfile: '/var/log/ntp.log'