tcpd.h: add prototype for hosts_ctl

According the hosts_access(3) man page the hosts_ctl() prototype
should be in tcpd.h. For now, follow other declarations and don't
add the arguments in the prototype.

Reference:
https://www.illumos.org/issues/4385

PR:		32808
MFC after:	2 weeks
Bump FreeBSD_version due to cleanup of tcp wrapper header.

Due to revisions r272949 and r272950 which should affect
positively some ports.
Do not set IN_ACCESS flag for read-only mounts.  The IN_ACCESS
survives remount in rw, also it is set for vnodes on rootfs before
noatime can be set or clock is adjusted.  All conditions result in
wrong atime for accessed vnodes.

Submitted by:	bde
MFC after:	1 week