rtc: add Intersil ISL12022 RTC driver

- derived from rtc-pcf8563

- no SRAM driver

Signed-off-by: Roman Fietze <roman.fietze@telemotive.de>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 6ed5e7e..999db51 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -203,6 +203,15 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-isl1208.
 
+config RTC_DRV_ISL12022
+	tristate "Intersil ISL12022"
+	help
+	  If you say yes here you get support for the
+	  Intersil ISL12022 RTC chip.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-isl12022.
+
 config RTC_DRV_X1205
 	tristate "Xicor/Intersil X1205"
 	help