powerpc/pseries: Add empty update_numa_cpu_lookup_table() for NUMA=n

When CONFIG_NUMA is not set, the build fails with:

  arch/powerpc/platforms/pseries/hotplug-cpu.c:335:4:
  error: déclaration implicite de la fonction « update_numa_cpu_lookup_table »

So we have to add update_numa_cpu_lookup_table() as an empty function
when CONFIG_NUMA is not set.

Fixes: 1d9a0907 ("powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove")
Signed-off-by: NCorentin Labbe <clabbe@baylibre.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/topology.h

@@ -81,6 +81,9 @@ static inline int numa_update_cpu_topology(bool cpus_locked)
 {
 	return 0;
 }
+
+static inline void update_numa_cpu_lookup_table(unsigned int cpu, int node) {}
+
 #endif /* CONFIG_NUMA */
 
 #if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)