pkgbase: Split out manpages by default

This helps with building small container images using pkgbase.

Reviewed by:	manu bapt
MFC after:	1 week
Differential Revision: https://reviews.freebsd.org/D41861

(cherry picked from commit 74da9c39c3460213750477204979989b5c39cbcd)

UPDATING

@@ -12,6 +12,11 @@ Items affecting the ports and packages system can be found in
 /usr/ports/UPDATING.  Please read that file before updating system packages
 and/or ports.
 
+20230924:
+	Enable splitting out pkgbase manpages into separate packages by
+	default. To disable this, set WITHOUT_MANSPLITPKG=yes in src.conf.
+
+
 20230924:
 	Move standard include files to the clibs-dev package and move clang
 	internal libraries and headers to clang and clang-dev. Upgrading systems

share/man/man5/src.conf.5

@@ -1157,8 +1157,8 @@ is set explicitly)
 .It Va WITHOUT_MANCOMPRESS
 Do not install compressed man pages.
 Only the uncompressed versions will be installed.
-.It Va WITH_MANSPLITPKG
-Split man pages into their own packages during make package.
+.It Va WITHOUT_MANSPLITPKG
+Do not split man pages into their own packages during make package.
 .It Va WITHOUT_MAN_UTILS
 Do not build utilities for manual pages,
 .Xr apropos 1 ,

share/mk/bsd.opts.mk

@@ -60,6 +60,7 @@ __DEFAULT_YES_OPTIONS = \
     MAKE_CHECK_USE_SANDBOX \
     MAN \
     MANCOMPRESS \
+    MANSPLITPKG \
     NIS \
     NLS \
     OPENSSH \
@@ -78,7 +79,6 @@ __DEFAULT_NO_OPTIONS = \
     INIT_ALL_PATTERN \
     INIT_ALL_ZERO \
     INSTALL_AS_USER \
-    MANSPLITPKG \
     PROFILE \
     RETPOLINE \
     STALE_STAGED \