vim: Improve locale handling

vim: Improve locale handling

When making checkouts from git, the timestamps can vary and occasionally two files
can end up with the same stamp. This triggers make to regenerate ru.cp1251.po from
ru.po for example. If it isn't regenerated, the output isn't quite the same leading
to reproducibility issues (CP1251 vs cp1251).

Since we added all locales to buildtools tarball now, we can drop the locale
restrictions too. We need to generate a native binary for the sjis conversion
tool so also tweak that.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>