drm/amd/powerplay: new cgs interface setting dpm thermal range

This will be used by powerplay to update the dpm temp range structure
used to interface with hwmon.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>