The OLD XSCALE stuff hasn't been useful in a while. The original
committer (cognet@) was the only one that had boards for it. He's
blessed this removal. Newer XSCALE (GUMSTIX) is for hardware that's
quite old. After discussion on arm@, it was clear there was no support
for keeping it.
Differential Review: https://reviews.freebsd.org/D16313
626930c2fd