add function smu_get_power_num_state function for sw-smu.
it's only for sysfs interface, the power state feature is not ready for sw-smu.
Signed-off-by: NKevin Wang <Kevin1.Wang@amd.com>
Reviewed-by: NHuang Rui <ray.huang@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>