wdt: dw: Switch to if(CONFIG()) instead of using #if

This is preferred over #if because the compiler can check syntax even if
the feature is disabled. This cannot be used for CONFIG_CLK because
CONFIG_DW_WDT_CLOCK_KHZ is not defined on all platforms.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/drivers/watchdog/designware_wdt.c b/drivers/watchdog/designware_wdt.c
index 1f0c5a7..a65487d 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -136,17 +136,17 @@
 	priv->clk_khz = CONFIG_DW_WDT_CLOCK_KHZ;
 #endif
 
-#if CONFIG_IS_ENABLED(DM_RESET)
-	struct reset_ctl_bulk resets;
+	if (CONFIG_IS_ENABLED(DM_RESET)) {
+		struct reset_ctl_bulk resets;
 
-	ret = reset_get_bulk(dev, &resets);
-	if (ret)
-		return ret;
+		ret = reset_get_bulk(dev, &resets);
+		if (ret)
+			return ret;
 
-	ret = reset_deassert_bulk(&resets);
-	if (ret)
-		return ret;
-#endif
+		ret = reset_deassert_bulk(&resets);
+		if (ret)
+			return ret;
+	}
 
 	/* reset to disable the watchdog */
 	return designware_wdt_stop(dev);