drm/amdgpu: always make gart.table_addr 64bit
Fixing warning/compile errors on 32bit kernels.
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>