apalis_imx6: add board_fit_config_name_match to support FIT in SPL

Only one dtb is currently supported, so match with imx6-apalis.

Signed-off-by: Ricardo Salveti <ricardo@foundries.io>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>