Add systemd auto-getty.service to run agetty on the console defined in the
kernel command line on platforms with systemd support.
This service replaces serial-getty@.service as the one responsible for
opening a tty port and prompting for a login name when
TRUSTFENCE_CONSOLE_DISABLE is configured.
https://jira.digi.com/browse/DEL-7242
Signed-off-by: Gonzalo Ruiz <Gonzalo.Ruiz@digi.com>