rtc: Add a driver for Micro Crystal RV8803

This driver supports the following functions:
 - reading and settings time
 - alarms when connected to an IRQ
 - reading and clearing the voltage low flags
 - nvram
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/Kconfig

@@ -593,6 +593,15 @@ config RTC_DRV_RV3029C2
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-rv3029c2.
 
+config RTC_DRV_RV8803
+	tristate "Micro Crystal RV8803"
+	help
+	  If you say yes here you get support for the Micro Crystal
+	  RV8803 RTC chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-rv8803.
+
 config RTC_DRV_S5M
 	tristate "Samsung S2M/S5M series"
 	depends on MFD_SEC_CORE

drivers/rtc/Makefile

@@ -126,6 +126,7 @@ obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o
 obj-$(CONFIG_RTC_DRV_RS5C348)	+= rtc-rs5c348.o
 obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o
 obj-$(CONFIG_RTC_DRV_RV3029C2)	+= rtc-rv3029c2.o
+obj-$(CONFIG_RTC_DRV_RV8803)	+= rtc-rv8803.o
 obj-$(CONFIG_RTC_DRV_RX4581)	+= rtc-rx4581.o
 obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o
 obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o