drm/amd/powerplay: add data structure of bootup values

This patch adds data structures for bootup values.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Kevin Wang <Kevin1.Wang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>