Path activation for dlog_logger.service

Path activation for dlog_logger.service

dlog_logger daemon writes its log into /var/log and /var is symlinked to
/opt/var. However, current dlog_logger.service sometimes failed to
launch because of "DefaultDependencies=no". In order to fix this bug,
dlog_logger.service should be launched just after '/var/log' is shown
and that means /opt is already mounted. This solution is also available
when using single root partition.

Change-Id: Ia1483d1806387f4a8cb5181f20b0adf30d33f305
Signed-off-by: Sangjung Woo <sangjung.woo@samsung.com>
Signed-off-by: chan lee <chan45.lee@samsung.com>