drm/amdgpu: update SMU driver interface for cyan skilfish(v3)

Add SmuMetrics_t definition for cyan skilfish.

v2: update SmuMetrics_t definition.
v3: cleanup and rearrange the order of fields.

Signed-off-by: Lang Yu <lang.yu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>