For computing PCIe bandwidth in userspace and troubleshooting PCIe
bandwidth issues. Note that this intentionally fills holes and padding
in drm_amdgpu_info_device.

Mesa MR: mesa/mesa!20790



Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>