drm/amdgpu: add DRIVER_SYNCOBJ_TIMELINE to amdgpu

Can expose it now that the khronos has exposed the
vlk extension.

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Flora Cui <Flora.Cui@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org