Build a 32-bit EFI loader on amd64. This to match the rest of the
code that is used to construct a loader (e.g. libstand, ficl, etc).

There is such a thing as a 64-bit EFI application, but it's not
as standard as 32-bit is. Let's make the 32-bit functional (as in
we can load and actualy boot a kernel) before solving the 64-bit
loader problem.