drm/amdgpu: support query vram info for sienna_cichlid

support query vram_module v11 and vram_info v2_5
for sienna_cichlid

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>