smegw01: Convert to watchdog driver model

Commit 68dcbdd594d4 ("ARM: imx: Add weak default reset_cpu()") caused
the 'reset' command in U-Boot to not cause a board reset.

Fix it by switching to the watchdog driver model via sysreset, which
is the preferred method for implementing the watchdog reset.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/arch/arm/dts/imx7d-smegw01-u-boot.dtsi b/arch/arm/dts/imx7d-smegw01-u-boot.dtsi
index 90f7500..611bfe5 100644
--- a/arch/arm/dts/imx7d-smegw01-u-boot.dtsi
+++ b/arch/arm/dts/imx7d-smegw01-u-boot.dtsi
@@ -1,3 +1,16 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
 
 #include "imx7s-u-boot.dtsi"
+
+/ {
+	wdt-reboot {
+		compatible = "wdt-reboot";
+		wdt = <&wdog1>;
+		bootph-pre-ram;
+	};
+};
+
+&wdog1 {
+	bootph-pre-ram;
+};
+
diff --git a/configs/smegw01_defconfig b/configs/smegw01_defconfig
index 13665ec..9f2cac7 100644
--- a/configs/smegw01_defconfig
+++ b/configs/smegw01_defconfig
@@ -81,5 +81,8 @@
 CONFIG_SPECIFY_CONSOLE_INDEX=y
 CONFIG_DM_SERIAL=y
 CONFIG_MXC_UART=y
+CONFIG_SYSRESET=y
+CONFIG_SYSRESET_WATCHDOG=y
 CONFIG_IMX_THERMAL=y
+CONFIG_IMX_WATCHDOG=y
 # CONFIG_CMD_BOOTEFI_BOOTMGR is not set