To fix WITHOUT_NIS build. Building yp_xdr.c is gated by MK_NIS.
PR: 279270
Reported by: peterj
Reported by: matteo
Reported by: Michael Dexter's Build Option Survey run
Reviewed by: brooks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D45347
(cherry picked from commit 61639bb3fc5abe0bb7b096e643b51c30703ac432)
These were left over from $FreeBSD$ removal.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D42612
(cherry picked from commit 1ca63a8219b88b752b064d19bd3428c61dbcf1f9)