drm/amdgpu: add pcie bif ras related registers

These registers will be accessed for querying ras errors.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>