src: fix type mismatch warnings from missing priv

Registration initialization functions are expected to have a 4th
argument, a void*, so add them where necessary to fix the warnings.

PR-URL: https://github.com/nodejs/node/pull/24737


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>