rtc: s5m: Move enum from rtc.h to rtc-s5m.c

Move this enum to rtc-s5m.c once it is meaningless to others drivers [1].

[1] https://marc.info/?l=linux-rtc&m=152060068925948&w=2

Suggested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c
index 6deae10..4c363de 100644
--- a/drivers/rtc/rtc-s5m.c
+++ b/drivers/rtc/rtc-s5m.c
@@ -38,6 +38,17 @@
  */
 #define UDR_READ_RETRY_CNT	5
 
+enum {
+	RTC_SEC = 0,
+	RTC_MIN,
+	RTC_HOUR,
+	RTC_WEEKDAY,
+	RTC_DATE,
+	RTC_MONTH,
+	RTC_YEAR1,
+	RTC_YEAR2,
+};
+
 /*
  * Registers used by the driver which are different between chipsets.
  *