pitx-imx8m: enable IMX watchdog

- guard u-boot execution using i.MX8 CPU watchdog
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

configs/pitx-imx8m_defconfig

@@ -33,7 +33,6 @@ CONFIG_SPL_POWER_SUPPORT=y
 CONFIG_SPL_USB_HOST_SUPPORT=y
 CONFIG_SPL_USB_GADGET=y
 CONFIG_SPL_USB_SDP_SUPPORT=y
-CONFIG_SPL_WATCHDOG_SUPPORT=y
 CONFIG_CMD_LICENSE=y
 CONFIG_CMD_BOOTZ=y
 CONFIG_CRC32_VERIFY=y
@@ -47,6 +46,7 @@ CONFIG_CMD_MMC=y
 CONFIG_CMD_READ=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_USB_MASS_STORAGE=y
+CONFIG_CMD_WDT=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_REGULATOR=y
 # CONFIG_ISO_PARTITION is not set
@@ -106,4 +106,6 @@ CONFIG_DM_VIDEO=y
 CONFIG_SYS_WHITE_ON_BLACK=y
 CONFIG_VIDEO_IMX8M_DCSS=y
 CONFIG_VIDEO_IMX8M_HDMI=y
+CONFIG_IMX_WATCHDOG=y
+CONFIG_WDT=y
 CONFIG_OF_LIBFDT_OVERLAY=y