Fixed license and copyright script errors with earlier change by
whitelisting newly introduced folder
build/linux/debian_jessie_arm64-sysroot.

This change modifies install-sysroot.py to add support for
installing ARM64 sysroot. also upadted jessie arm64 package list.

BUG=613452
R=thestig@chromium.org

Review-Url: https://codereview.chromium.org/2136993002
Cr-Commit-Position: refs/heads/master@{#404719}