rtc: add support for DS3232 RTC

Add a driver for the DS3232 RTC chip via the I2C bus.  Alarms are not
supported in this version of the driver.

[akpm@linux-foundation.org: fix Kconfig help text]
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Jingchang Lu <b22599@freescale.com>
Signed-off-by: Srikanth Srinivasan <srikanth.srinivasan@freescale.com>
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Cc: Kumar Gala <kumar.gala@freescale.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 999db51..06cb8d6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -166,6 +166,16 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds1672.
 
+config RTC_DRV_DS3232
+	tristate "Dallas/Maxim DS3232"
+	depends on RTC_CLASS && I2C
+	help
+	  If you say yes here you get support for Dallas Semiconductor
+	  DS3232 real-time clock chips.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called rtc-ds3232.
+
 config RTC_DRV_MAX6900
 	tristate "Maxim MAX6900"
 	help