rtc: driver for the DryIce block found in i.MX25 chips

This driver is based on code from Freescale which accompanies their i.MX25
PDK board, with some cleanup.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Sascha Hauer <kernel@pengutronix.de>
Acked-by: 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 4301a6c..6ed5e7e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -537,6 +537,16 @@
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-msm6242.
 
+config RTC_DRV_IMXDI
+	tristate "Freescale IMX DryIce Real Time Clock"
+	depends on ARCH_MX25
+	depends on RTC_CLASS
+	help
+	   Support for Freescale IMX DryIce RTC
+
+	   This driver can also be built as a module, if so, the module
+	   will be called "rtc-imxdi".
+
 config RTC_MXC
 	tristate "Freescale MXC Real Time Clock"
 	depends on ARCH_MXC