MFC note: only the newsyslog.conf.d change has been backported to unbreak

MFC note:	only the newsyslog.conf.d change has been backported to unbreak
		"make distribution" with etc/newsyslog.conf.d/opensm.conf
		installation. The cron.d and syslog.d changes were omitted by
		request to avoid churn on ^/stable/{10,11}.
Requested by:	jhb, peter

MFC r318545:

Install {cron.d,newsyslog.conf.d,syslog.d} via `make distribution`, not `make install`

I incorrectly started this pattern in r277541 with the opensm newsyslog.conf.d file,
and continued using it in r318441 and r318443.

This will fix the files being handled improperly via installworld, preventing tools like
etcupdate, mergemaster, etc from functioning properly when comparing the installed
contents on a system vs the contents in a source tree when doing merges.

PR:		219404
MFC with:	r277541, r318441, r318443

git-svn-id: svn://svn.freebsd.org/base/stable/10@321251 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f