driver: watchdog: reset watchdog in designware_wdt_stop() function

In uboot command line environment, watchdog is not able to be
stopped with below commands:
SOCFPGA_STRATIX10 # wdt dev watchdog@ffd00200
SOCFPGA_STRATIX10 # wdt stop
Refer to watchdog driver in linux kernel, it is also need to reset
watchdog after disable it so that the disable action takes effect.

Signed-off-by: Meng Li <Meng.Li@windriver.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/drivers/watchdog/designware_wdt.c b/drivers/watchdog/designware_wdt.c
index 9e54871..afed81e 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -22,6 +22,7 @@
 struct designware_wdt_priv {
 	void __iomem	*base;
 	unsigned int	clk_khz;
+	struct reset_ctl_bulk *resets;
 };
 
 /*
@@ -95,6 +96,18 @@
 	designware_wdt_reset(dev);
 	writel(0, priv->base + DW_WDT_CR);
 
+        if (CONFIG_IS_ENABLED(DM_RESET)) {
+		int ret;
+
+		ret = reset_assert_bulk(priv->resets);
+		if (ret)
+			return ret;
+
+		ret = reset_deassert_bulk(priv->resets);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -143,13 +156,11 @@
 #endif
 
 	if (CONFIG_IS_ENABLED(DM_RESET)) {
-		struct reset_ctl_bulk resets;
-
-		ret = reset_get_bulk(dev, &resets);
+		ret = reset_get_bulk(dev, priv->resets);
 		if (ret)
 			goto err;
 
-		ret = reset_deassert_bulk(&resets);
+		ret = reset_deassert_bulk(priv->resets);
 		if (ret)
 			goto err;
 	}