watchdog: add support for the Synopsys DesignWare WDT

The Synopsys DesignWare watchdog is found in several ARM based systems
and provides a choice of 16 timeout periods depending on the clock
input.  The watchdog cannot be disabled once started.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 21d816e..de78d0a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -186,6 +186,15 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called sa1100_wdt.
 
+config DW_WATCHDOG
+	tristate "Synopsys DesignWare watchdog"
+	depends on ARM && HAVE_CLK
+	help
+	  Say Y here if to include support for the Synopsys DesignWare
+	  watchdog timer found in many ARM chips.
+	  To compile this driver as a module, choose M here: the
+	  module will be called dw_wdt.
+
 config MPCORE_WATCHDOG
 	tristate "MPcore watchdog"
 	depends on HAVE_ARM_TWD