pmic808: support rtc power on feature.

RK817_RTC_INT_REG(0x12) Bit(3)(RTC_INT_REG) was for RTC Alarm interrupt
enable or disable. Default driver will disable RTC interrupt before shutdown.
Keep RTC interrupt enable then device can support RTC power on feature

Change-Id: I4ac74954a9f98f4c3bd6b6121132dd55d45a1746
Signed-off-by: yi-hsin_hung <yi-hsin_hung@asus.com>

Author: yihsin-hung

drivers/mfd/rk808.c

@@ -849,7 +849,7 @@ static void rk808_syscore_shutdown(void)
 			   (0x3 << 5), (0x3 << 5));
 	regmap_update_bits(rk808->regmap,
 			   RK808_RTC_INT_REG,
-			   (0x3 << 2), (0x0 << 2));
+			   (0x1 << 2), (0x0 << 2));
 	/*
 	 * For PMIC that power off supplies by write register via i2c bus,
 	 * it's better to do power off at syscore shutdown here.