cldr2def.pl: Fix make install

Follow up on 86c71e97d19f ("pkgbase: locales: Also tag the files dir"),
and adapt cldr2def.pl script in order to fix make install.

Reviewed by: bapt
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D53961

(cherry picked from commit 95f37aa3e51ce46821059b2c9dbb02fef5c4bec5)