rtc: AB3100 RTC support

This adds support for the RTC found inside the AB3100 Mixed Signal chip.
The symbols used for communicating with the chip is found in the
mfd/ab3100-core.c driver that also provides the platform device.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index f3e5735..5e152ff 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -17,6 +17,7 @@
 
 # Keep the list ordered.
 
+obj-$(CONFIG_RTC_DRV_AB3100)	+= rtc-ab3100.o
 obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o
 obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o
 obj-$(CONFIG_RTC_DRV_AT91SAM9)	+= rtc-at91sam9.o