systemd: Use overlay for specifying watchdog parameters

There's no reason to sed stuff. This way also makes it easier to support
running with empty /etc.

Change-Id: I16c0dba53682df574ee119951f47c7c6d4071d61
4 files changed
tree: a68b669574f4546b95b27af934c356025cdf4329
  1. Config.in
  2. board/
  3. configs/
  4. external.desc
  5. external.mk
  6. package/