This moves PIR/PURR/SPURR SPRs to helpers. Later these helpers will be
called from generalized init_proc_book3s_64().
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>