drm/amdgpu: remove gfxhub_v1_1_funcs set

remove duplicate gfxhub v1.1 function set.
put function of gfxhub_v1_1_get_xgmi_info to gfxhub v1_0 function set.

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>