drm/amdgpu: add gfxhub_v3_0_3 support

add gfxhub_v3_0_3 support

Signed-off-by: Yang Wang <KevinYang.Wang@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>