drm/amdgpu: add CSDMA reg offsets for NBIO v7.7.0

This patch will add CSDMA reg offsets for NBIO v7.7.0

Signed-off-by: Xiaojian Du <Xiaojian.Du@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>