drm/amd/powerplay: move read sensor of UVD[VCE]_POWER to amdgpu_smu file

This part of code is asic unrelated and moves to top code level.

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>