dm: sysreset: add watchdog-reboot driver

Add a new sysreset driver that uses the recently added watchdog support.
It performs a full SoC reset by calling wdt_expire_now op.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index b2f7464..a6d48e8 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -31,4 +31,10 @@
 	help
 	  Reboot support for generic SYSCON mapped register reset.
 
+config SYSRESET_WATCHDOG
+	bool "Enable support for watchdog reboot driver"
+	select WDT
+	help
+	  Reboot support for generic watchdog reset.
+
 endmenu