watchdog: max77620: Add support for watchdog timer

Maxim PMIC MAX77620 is Power management IC which have multiple
sub blocks like regulators (DCDC/LDOs), GPIO, RTC, Clock, Watchdog
timer etc.

Add the driver for watchdog timer under watchdog framework.
The driver implements the watchdog callbacks to start, stop,
ping and set timeout for watchodg framework.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index a12bf54..65058d6 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -516,6 +516,15 @@
 	help
 	  Support for memory mapped max63{69,70,71,72,73,74} watchdog timer.
 
+config MAX77620_WATCHDOG
+	tristate "Maxim Max77620 Watchdog Timer"
+	depends on MFD_MAX77620
+	help
+	 This is the driver for the Max77620 watchdog timer.
+	 Say 'Y' here to enable the watchdog timer support for
+	 MAX77620 chips. To compile this driver as a module,
+	 choose M here: the module will be called max77620_wdt.
+
 config IMX2_WDT
 	tristate "IMX2+ Watchdog"
 	depends on ARCH_MXC || ARCH_LAYERSCAPE