Always-on PM domains must be on during initialisation or the domain is
currently silently rejected.

Print an error message in case an always-on domain is not on to make it
easier to debug drivers getting this wrong (e.g. by setting an always-on
genpd flag without making sure that the state matches).
Signed-off-by: NJohan Hovold <johan+linaro@kernel.org>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>