watchdog: Add Realtek RTD1295

Add a watchdog driver for the Realtek RTD1295 SoC.

Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_watchdog.c code and
mach-rtk119x/driver/dc2vo/fpga/include/iso_reg.h register defines.

Signed-off-by: Andreas Färber <afaerber@suse.de>
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 5a606a4..6fdf3f9 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -787,6 +787,16 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called uniphier_wdt.
 
+config RTD119X_WATCHDOG
+	bool "Realtek RTD119x/RTD129x watchdog support"
+	depends on ARCH_REALTEK || COMPILE_TEST
+	depends on OF
+	select WATCHDOG_CORE
+	default ARCH_REALTEK
+	help
+	  Say Y here to include support for the watchdog timer in
+	  Realtek RTD1295 SoCs.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT