As glibc 2.27 can't read older locale-archives, SDKs using glibc 2.27 on hosts
using glibc earlier than 2.27 won't be able to find any locales, so bitbake
won't start and Python can't use UTF-8.
So by default install all locales into the SDK. Special-case Extensible SDKs by
installing no locales as they ship glibc in a buildtools, and that will have the
locales.
Locale installation requires cross-localedef, so add that to DEPENDS.
Also remove the explicit en_US addition in buildtools-tarball as it is now
redundant.
Signed-off-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
