[PATCH] powerpc: fix for compile problem in kdump code when SMP disabled

This patch fixes the compilation error (shown below) when CONFIG_SMP=n.
    arch/powerpc/kernel/crash.c: In function `crash_kexec_prepare_cpus':
    arch/powerpc/kernel/crash.c:236: error: implicit declaration of
    function `smp_release_cpus'
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/crash.c

@@ -18,7 +18,6 @@
 #include <linux/kexec.h>
 #include <linux/bootmem.h>
 #include <linux/crash_dump.h>
-#include <linux/irq.h>
 #include <linux/delay.h>
 #include <linux/elf.h>
 #include <linux/elfcore.h>
@@ -30,6 +29,7 @@
 #include <asm/kdump.h>
 #include <asm/lmb.h>
 #include <asm/firmware.h>
+#include <asm/smp.h>
 
 #ifdef DEBUG
 #include <asm/udbg.h>