drm/amdgpu/soc15: add Raven golden setting

Add the common golden settings for Raven.

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>