Documentation: Remove the unused "topology_updates" from kernel-parameters.txt

The "topology_updates" switch has been removed four years ago in commit
c30f931e ("powerpc/numa: remove ability to enable topology updates"),
so let's remove this from the documentation, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240617060848.38937-1-thuth@redhat.com