drm/amdgpu: add amdgpu_gtt_node_to_byte_offset helper
Having a helper avoids code duplication.
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
authored by