imx8m: Select BINMAN at SoC level

All i.MX8M targets rely on using binman to generate the U-Boot
binary.

Select it at the SoC level instead of per board.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
1 file changed