rtc: add ht1380 driver

Support Holtek HT1380/HT1381 Serial Timekeeper Chip. It provides seconds
, minutes, hours, day of the week, date, month and year information.

Datasheet:
https://www.holtek.com.tw/documents/10179/11842/ht1380_1v130.pdf

Signed-off-by: Sergei Antonov <saproj@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index b698722..35b6ed4 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -260,4 +260,13 @@
 	  Say "yes" here to support the on chip real time clock
 	  present on Xilinx ZynqMP SoC.
 
+config RTC_HT1380
+	bool "Enable Holtek HT1380/HT1381 RTC driver"
+	depends on DM_RTC && DM_GPIO
+	help
+	  Say "yes" here to get support for Holtek HT1380/HT1381
+	  Serial Timekeeper IC which provides seconds, minutes, hours,
+	  day of the week, date, month and year information. It is to be
+	  connected via 3 GPIO pins which work as reset, clock, and data.
+
 endmenu