Move all dependency post-processing to util/add-depends.pl

In the end, it's more efficient to only have one perl instance (that
loads configdata.pm) dealing with dependency files than running one
(that still loads configdata.pm) for each such file.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5631)