depends: zlib: Move toolchain options to configure

Summary:

zlib has its own custom configure script, see comment in zlib.mk for
more details

Backport of core PR16809.

Test Plan: Run the Gitian builds.

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5655