rtc: add alarm related features

Add more alarm related features to be declared by drivers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211018151933.76865-2-alexandre.belloni@bootlin.com

include/uapi/linux/rtc.h

@@ -114,7 +114,9 @@ struct rtc_pll_info {
 #define RTC_FEATURE_ALARM		0
 #define RTC_FEATURE_ALARM_RES_MINUTE	1
 #define RTC_FEATURE_NEED_WEEK_DAY	2
-#define RTC_FEATURE_CNT			3
+#define RTC_FEATURE_ALARM_RES_2S	3
+#define RTC_FEATURE_UPDATE_INTERRUPT	4
+#define RTC_FEATURE_CNT			5
 
 #define RTC_MAX_FREQ	8192