If no valid state idx specified by governor, we use the default state_idx 0 to enter in case the domain has multi low power states. Reviewed-by: Frank Li <frank.li@nxp.com> Reviewed-by: Ranjani Vaidyanathan <Ranjani.Vaidyanathan@nxp.com> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>