powerpc/85xx: add DOZE/NAP support for e500 core

The e500 core enter DOZE/NAP power-saving modes when the core go to
cpu_idle routine.

The power management default running mode is DOZE, If the user

echo 1 > /proc/sys/kernel/powersave-nap

the system will change to NAP running mode.

Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index 54ed64d..9899226 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -262,6 +262,7 @@
 #endif
 };
 
+extern void e500_idle(void);
 extern void power4_idle(void);
 extern void power4_cpu_offline_powersave(void);
 extern void ppc6xx_idle(void);