PNOR: Create a service file for updating symlinks.

- Replace the functionality of updating the symlinks
  under openpower-pnor-code-mgmt to a service file.
- The new service has a dependency on mboxd.service.
  This allows us to only defer the symlink creation/update
  until the mboxd.service is started, which prevents
  symlink updates while HOST is running.

Change-Id: I8542aa24a9058af9560a32eec5140ff5ddee60d1
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
3 files changed