strace: Use locale-base-en-us for locale

locale-base-en-us is available on musl as well therefore, not need
to make it glibc specific anymore.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>