rtc: add support for rv3028 rtc

Add support for rtc3028 rtc from microcrystal.
based on linux dirver:
commit a38fd8748464: ("Linux 5.12-rc2")

Signed-off-by: Heiko Schocher <hs@denx.de>

Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 15609e7..f668cf9 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -47,6 +47,7 @@
 obj-$(CONFIG_RTC_PL031) += pl031.o
 obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o
 obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o
+obj-$(CONFIG_RTC_RV3028) += rv3028.o
 obj-$(CONFIG_RTC_RV3029) += rv3029.o
 obj-$(CONFIG_RTC_RV8803) += rv8803.o
 obj-$(CONFIG_RTC_RX8025) += rx8025.o