imx8mn_beacon: Fix booting hang and switch to binman

Somewhere along the line, the board stopped being able to boot.
Rather than just fixing the issue, let's fix the issue and migrate
to binman to eliminate a warning when using custom imx tools for
generating the binary.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
5 files changed