topology: Set capacity_freq_ref in all cases

If "capacity-dmips-mhz" is not set, raw_capacity is null and we skip the
normalization step which includes setting per_cpu capacity_freq_ref.
Always register the notifier but skip the capacity normalization if
raw_capacity is null.

Fixes: 9942cb22

 ("sched/topology: Add a new arch_scale_freq_ref() method")
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20240117190545.596057-1-vincent.guittot@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>