Explicitly label .origin files as configuration

Explicitly label .origin files as configuration

subscription-manager has a daemon that runs in a confined domain,
and it doesn't have permission to write usr_t, which is the default
label of /ostree/deploy/$osname/deploy.

A better long term fix is probably to move the origin file into the
deployment root as /etc/ostree/origin.conf or so.

In the meantime, let's ensure the .origin files are labeled as
configuration.