powerpc/pseries: Fix CONFIG_NUMA=n build

powerpc/pseries: Fix CONFIG_NUMA=n build

BugLink: http://bugs.launchpad.net/bugs/1794889
[ Upstream commit 6c0a8f6b5a45ac892a763b6299bd3c5324fc5e02 ]

The build is failing with CONFIG_NUMA=n and some compiler versions:

  arch/powerpc/platforms/pseries/hotplug-cpu.o: In function `dlpar_online_cpu':
  hotplug-cpu.c:(.text+0x12c): undefined reference to `timed_topology_update'
  arch/powerpc/platforms/pseries/hotplug-cpu.o: In function `dlpar_cpu_remove':
  hotplug-cpu.c:(.text+0x400): undefined reference to `timed_topology_update'

Fix it by moving the empty version of timed_topology_update() into the
existing #ifdef block, which has the right guard of SPLPAR && NUMA.

Fixes: cee5405da402 ("powerpc/hotplug: Improve responsiveness of hotplug change")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>