Update cluster_policy_get_all to no longer query uneeded tables
Update cluster_policy_get_all to no longer query uneeded tables

This patch removes the model_query function from
cluster_policy_get_all to avoid returning unused rows from the
database. This reduces the query time of the action.

Change-Id: Ia919e7ab491428b9adb4724969bdff4189104ef3

openstack/senlin,stackforge/senlin,openstack/senlin,stackforge/senlin,openstack/senlin