tlsdate: Buildfix for ARM64

Fixed build in case of arm64-generic overlay.
Added the seccomp filter file for arm64, and updated the list to
match the aarch64 syscalls.

BUG=none
TEST=compiled for arm64-generic overlay

Change-Id: Idfc737d4f30c45b47a8a75aed862c32390fccf9d
Reviewed-on: https://chromium-review.googlesource.com/1047227
Commit-Ready: Daniel Batyai <dbatyai@inf.u-szeged.hu>
Tested-by: Daniel Batyai <dbatyai@inf.u-szeged.hu>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed