powerpc: move a stray NMI IPI case under NMI_IPI ifdef

Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/smp.c

@@ -194,7 +194,9 @@ const char *smp_ipi_name[] = {
 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 	[PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
 #endif
+#ifdef CONFIG_NMI_IPI
 	[PPC_MSG_NMI_IPI] = "nmi ipi",
+#endif
 };
 
 /* optional function to request ipi, for controllers with >= 4 ipis */