drm/amdgpu: expose GPU sensor related information
This includes shader/memory clocks, temperature, GPU load, etc.
v2: - add sub-queries for AMDPGU_INFO_GPU_SENSOR_*
- do not break the ABI
v3: - return -ENOENT when amdgpu_dpm == 0
- expose more sensor queries
v4: - s/GPU_POWER/GPU_AVG_POWER/
- improve VDDNB/VDDGFX query description
- fix amdgpu_dpm check
v5: - agd: fix warning
v6: - agd: bump version
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>