rainier: systemd and journal defaults

Use the defaults from witherspoon for now. With more space available in
the rainier rootfs, we may tweak these in the future.

(From meta-ibm rev: 6e733b66f460ffc03d27c81139ed318bc8c8583e)

Change-Id: I66691a06854ab44173fa519e5f95fedbcdb2b6fa
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>