drm/amd/pm: Set no fan control flag as needed.

For GPUs that don't support fan control, set the no fan control flag so
that they don't appear in hwmon sensors.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>