buildtools-extended-tarball: Add locale command

The eSDK installation code checks installed locales with the locale command which is
from glibc-utils. Add this so that we find the correct locales from the buildtools.

(From OE-Core rev: 7d35e4bc)

(From OE-Core rev: d99b6432)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>