lakitu: Remove NTP_SERVER related from systemd

systemd now uses chrony as NTP server, and the compilation option
is not necessary. Remove them.

$ cat /etc/chrony/chrony.conf
# Use custom NTP servers
server metadata.google.internal prefer iburst

BUG=b/169782038
TEST=sponge2/2fbdf850-2849-4fdd-947d-ed09c88e9d91 and cat /etc/chrony/chrony.conf
     to verify that NTP server is  metadata.google.internal
RELEASE_NOTE=None

Change-Id: I540f3d066fbb684113fbca10536bbd4a3184e3ca
2 files changed