drm/amdgpu: add UMSCH 4.0 register headers
Add headers for UMSCH 4.0.
v2: updates (Alex)
Signed-off-by: Lang Yu <Lang.Yu@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: Veerabadhran Gopalakrishnan <Veerabadhran.Gopalakrishnan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
authored by