iso-image: Use fixed-order mcopy instead of file globbing
iso-image: Use fixed-order mcopy instead of file globbing

mcopy file globbing is non-deterministic with respect to the underlying file
system. As a result, the current mcopy approach is less likely to reproduce
efi.img on different machines. We replace mcopy file globbing with
fixed-order mmd and mcopy operations for better determinism. We also use
faketime on mmd for the same reason. We use faketime, mmd, and mcopy
directly, becase they are already in PATH.

Thank misuzu@ for the feedback.

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