Remove selinux from os-svc-install element-deps

os-collect-config depends on os-svc-install, so non-tripleo images
are getting tripleo selinux policies installed on them. This is
making o-r-c runs much slower for no benefit (and sometimes making
o-r-c exit with an error http://paste.openstack.org/show/135018/)

Change-Id: I90a8fb67e688ed068b5e7123e76aeced9af968b1
Merge "Remove selinux from os-svc-install element-deps"