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/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