igw: Add selinux support for ceph iscsi

igw: Add selinux support for ceph iscsi

This adds selinux support for the ceph iscsi daemons under the ceph
github:

ceph-iscsi-config - rbd-target-gw
ceph-iscsi-cli - rbd-target-api

We use tcmu-runner, but that will go into the core policy to avoid
conflicts with gluster and distro bases.

This requires the patches:

https://github.com/ceph/ceph-iscsi-config/pull/90
https://github.com/ceph/ceph-iscsi-cli/pull/134

Signed-off-by: Mike Christie <mchristi@redhat.com>