drm/amdgpu: Add athub v4_1_0 ip block support

Add athub v4_1_0 ip block support.

v2: fix clang warning (Alex)

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>