[WATCHDOG] Add support for WM831x watchdog

The WM831x series of devices provide a watchdog with configurable
behaviour on timer expiry.

Currently this driver support refreshes via a register or GPIO line and
autonomous refreshes from a hardware source (eg, a clock).

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 3229889..ff3eb8f 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -55,6 +55,13 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called softdog.
 
+config WM831X_WATCHDOG
+	tristate "WM831x watchdog"
+	depends on MFD_WM831X
+	help
+	  Support for the watchdog in the WM831x AudioPlus PMICs.  When
+	  the watchdog triggers the system will be reset.
+
 config WM8350_WATCHDOG
 	tristate "WM8350 watchdog"
 	depends on MFD_WM8350