autoprovision: split script+unit into separate files

Now that we're using Jinja to render the kickstart scripts, we can
separate out scripts, systemd unit files, etc. into their own files and
`include` them.  This makes editing them much easier, especially since
syntax highlighting will work correctly.

fedora-rpi.ks.j2

@@ -2,4 +2,4 @@
 ignoredisk --only-use /dev/mmcblk0
 {% include "fedora-disk-dch.ks" %}
 {% include "fedora-rpi-common.ks.j2" %}
-{% include "autoprovision.ks" %}
+{% include "autoprovision.ks.j2" %}