drm/amdgpu: wire up defines, shifts and masks through SI code

drm/amdgpu: wire up defines, shifts and masks through SI code

To be able to remove as much duplicated defines, the different files
containing definitions, shifts and masks must be properly included.

Once done, the code will be migrated where needed to shifts and masks and
proper defines, before removing useless defines in the end.

Signed-off-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>