This expands on D24361, splitting FDT into a separate file and adding ACPI, to support the SolidRun LX2160A CEX7 module (e.g. on the SolidRun HoneyComb LX2K workstation board).
Ignore the `files.arm64` for now, I can fix that after merge (note: I don't like the `SOC_NXP_LS1046A` option, that's overly specific, this kind of hardware is common to the whole layerscape family)