drm/amdgpu: add atombios headers

These headers define the atombios table structure and
driver interface.

Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --cc drivers/gpu/drm/amd/amdgpu/ObjectID.h
Simple merge

diff --cc drivers/gpu/drm/amd/amdgpu/atombios.h
Simple merge

diff --cc drivers/gpu/drm/amd/amdgpu/pptable.h
Simple merge