add sensor interface of gfx vdd for hwmon
Signed-off-by: NKevin Wang <Kevin1.Wang@amd.com>
Reviewed-by: NHuang Rui <ray.huang@amd.com>
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>