add swupdate specific systemd-tmpfiles configuration file
Created by: 0xa5a5
The default systemd-tmpfiles configuration for the /tmp directory (tmp.conf) causes systemd-tmpfiles-clean.service to remove the folders /tmp/datadst and /tmp/scripts if they are not used for >=10 days.
SWUpdate creates these directories on startup (swupdate_init) and assumes their existence on use.
For this reason, an SWUpdate specific systemd-tmpfiles configuration is installed, in order to guarantee that the two directores above are preserved (only the folders, not their content).