[POWERPC] celleb: fix CONFIG_KEXEC dependency

celleb_kexec_cpu_down() depends on CONFIG_KEXEC.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/celleb/setup.c b/arch/powerpc/platforms/celleb/setup.c
index 1de63ac..5f4d0d9 100644
--- a/arch/powerpc/platforms/celleb/setup.c
+++ b/arch/powerpc/platforms/celleb/setup.c
@@ -137,10 +137,12 @@
 	return -ENODEV;
 }
 
+#ifdef CONFIG_KEXEC
 static void celleb_kexec_cpu_down(int crash, int secondary)
 {
 	beatic_deinit_IRQ();
 }
+#endif
 
 static struct of_device_id celleb_bus_ids[] = {
 	{ .type = "scc", },