mfd: rk808: Use DEFINE_RES_IRQ for rk808 RTC alarm IRQ

Do not open code the definition, instead use the nice DEFINE_RES_IRQ
macro for it.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
index c0e5e92..a69a674 100644
--- a/drivers/mfd/rk808.c
+++ b/drivers/mfd/rk808.c
@@ -109,11 +109,7 @@ static const struct regmap_config rk817_regmap_config = {
 };
 
 static struct resource rtc_resources[] = {
-	{
-		.start  = RK808_IRQ_RTC_ALARM,
-		.end    = RK808_IRQ_RTC_ALARM,
-		.flags  = IORESOURCE_IRQ,
-	}
+	DEFINE_RES_IRQ(RK808_IRQ_RTC_ALARM),
 };
 
 static struct resource rk817_rtc_resources[] = {