mfd: Add ability to wake the system for 88pm860x

For 88pm860x pmic, it can wake the system from low power mode by irq,
its sub-devs like RTC and onkey can be enabled for this usage.

Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/include/linux/mfd/88pm860x.h b/include/linux/mfd/88pm860x.h
index 92be3476..8b583f3 100644
--- a/include/linux/mfd/88pm860x.h
+++ b/include/linux/mfd/88pm860x.h
@@ -311,6 +311,7 @@
 	int			core_irq;
 	unsigned char		chip_version;
 
+	unsigned int            wakeup_flag;
 };
 
 enum {