drm/amd/pm: fix the wrong fan speed in fan1_input

fix the wrong fan speed in fan1_input when the fan control mode is manual.
the fan speed value is not correct when we set manual mode to fan1_enalbe - 1.
since the fan speed in the metrics table always reflects the real fan speed,we
can fetch the fan speed for both auto and manual mode.

Signed-off-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>