Fix aarch/arm64 Architecture Issues

[jxmx]

This pull request addresses two things:

• Fixed the architecture mismatch in #239 by adding a statement to read the basic config in before generating the board-related configuration
• A better fix for the logic on when qemu-arm-static isn't needed (e.g. building an aarch64 image on an aarch64 system). This replaces my old pull #228