Integrate u-boot-seco-imx/c72n-fix-default-env

Commit: edgehog/bsp/nxp/u-boot-seco-imx@457f1fb6

[C72n][ENV] fix default root device id

By default, env variable root_device_id is 1 (uSD) while fdt_device_id, kernel_device_id, ramfs_device_id, etc are 0 (MMC). Set all to 0 for c72n