etc/mtree: Restore removed package tags

Following commit 436618a427 which added package tags to mtree,
some of the tags were later removed due to an issue with empty
packages being created.  That problem has been fixed by commit
7965c93e4d, so we can now restore the tags that were removed.

This reverts commit 00352ef6d2.
This reverts commit 1fbdb149aa.
This reverts commit ef2d586d7e.
This reverts commit 2a8a6179eb.

MFC after:	2 weeks (stable/15 only)
Reviewed by:	des, bapt, emaste
Differential Revision:	https://reviews.freebsd.org/D55645
Sponsored by:		https://www.patreon.com/bsdivy

etc/mtree/BSD.include.dist

@@ -6,13 +6,13 @@
 .
     arpa
     ..
-    atf-c
+    atf-c               tags=package=atf-dev
     ..
-    atf-c++
+    atf-c++             tags=package=atf-dev
     ..
     bsm                 tags=package=audit-dev
     ..
-    bsnmp
+    bsnmp               tags=package=bsnmp-dev
     ..
     c++
         v1
@@ -278,9 +278,9 @@
     ..
     lib9p               tags=package=lib9p-dev
     ..
-    libipt
+    libipt              tags=package=libipt-dev
     ..
-    libmilter
+    libmilter           tags=package=libmilter-dev
     ..
     libxo               tags=package=runtime-dev
     ..