move mon_max_pg_per_osd to global section

Change-Id: I12f53878333bcca9b336aae857c6bc634076893c
Related-Prod: PROD-29811
diff --git a/metadata/service/common/single.yml b/metadata/service/common/single.yml
index 7aec939..c81947b 100644
--- a/metadata/service/common/single.yml
+++ b/metadata/service/common/single.yml
@@ -5,6 +5,9 @@
     ceph_mon_node01_hostname: cmn01
   ceph:
     common:
+      config:
+        global:
+          mon_max_pg_per_osd: 600
       enabled: true
       version: ${_param:ceph_version}
       fsid: ${_param:ceph_cluster_fsid}