build_package.sh: strip first component from mbedtls archive

Mbedtls tarballs (or zips) are packaged including the
<projects-name>-<version> as root folder, so this one must be stripped
when extracting it for a proper setup.

Change-Id: Iea2b4af0655e93b31bdd5122d65d43b8144570d9
Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
2 files changed