watchdog: introduce retu_wdt driver

Introduce Retu watchdog driver.

Cc: linux-watchdog@vger.kernel.org
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bb74186..7f61687 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -377,6 +377,18 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called ux500_wdt.
 
+config RETU_WATCHDOG
+	tristate "Retu watchdog"
+	depends on MFD_RETU
+	select WATCHDOG_CORE
+	help
+	  Retu watchdog driver for Nokia Internet Tablets (770, N800,
+	  N810). At least on N800 the watchdog cannot be disabled, so
+	  this driver is essential and you should enable it.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called retu_wdt.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT