rtc: rv3028: add new driver

Add a driver for the MicroCrystal RV-3028. It is a SMT Real-Time Clock
Module that incorporates an integrated CMOS circuit together with an XTAL.
It has an i2c interface.

The driver handles date/time, alarms, trickle charging, timestamping,
frequency offset correction, EEPROM and NVRAM.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 7d61bb3..a08785a 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -626,6 +626,15 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-em3027.
 
+config RTC_DRV_RV3028
+	tristate "Micro Crystal RV3028"
+	help
+	  If you say yes here you get support for the Micro Crystal
+	  RV3028.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-rv3028.
+
 config RTC_DRV_RV8803
 	tristate "Micro Crystal RV8803, Epson RX8900"
 	help