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/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index bef0be3..9e83add 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -127,6 +127,11 @@
 		ppc_md.power_save = ppc6xx_idle;
 #endif
 
+#ifdef CONFIG_E500
+	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
+	    cpu_has_feature(CPU_FTR_CAN_NAP))
+		ppc_md.power_save = e500_idle;
+#endif
 	if (ppc_md.progress)
 		ppc_md.progress("id mach(): done", 0x200);
 }