audio/rplay: Deprecate and set expiration date to 2021-12-31

Abandoned upstream, no new release since 1999 and considered dead
Reported broken on amd64 in 2012 in fix never confirmed working, PR: 166658

Reference:
http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/audio/rplay/Attic/Makefile

PR:		258647
Approved by:	tcberner (mentor)
Differential Revision:	https://reviews.freebsd.org/D32044