bitbake.conf: change localedir

bitbake.conf: change localedir

Previously, localedir is set to "${libdir}/locale". This would result
in locale database installed in '/usr/lib64/locale' in some multilib case.
For example, if we build out a multilib x86-64 self-hosted image and we try
to build projects on this host, things broke and the following error appears.

  Please use a locale setting which supports utf-8.
  Python can't change the filesystem locale after loading so we need a utf-8 when python starts or things won't work.

This is because '/usr/lib/locale' is the default one. And actually the
nativesdk-glibc is now set to use '/usr/lib/locale'.

Thus, we change the setting of 'localedir' to '${nonarch_libdir}/locale' to
fix the above problem.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>