deps: add missing legacyprov.c source

This commit add the missing legacy provider source code which is
requried for statically linking the OpenSSL legacy provider.

Co-authored-by: Richard Lau <rlau@redhat.com>

PR-URL: https://github.com/nodejs/node/pull/40478
Refs: https://github.com/nodejs/node/issues/40455


Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>