man: Install more man pages unconditionally

Add more manual pages which were not spotted previously in 0a0f7486413c

Ideally to be MFH'ed with:

8539518055d0 - Remove manpages from OLD_FILES
8b487b8292e4 - Fix bsd.subdir.mk-related issues after 0a0f7486413c
f6043a672135 - ObsoleteFiles.inc: Remove manpages from OLD_FILES
0a0f7486413c - man: Build manpages for all architectures

There is at least one pending issue when building with -DNO_ROOT.

Reported by: ceri@
MFH: 4 weeks
Discussed with: wosch
Differential Revision: https://reviews.freebsd.org/D31018