[CI] Make the build_autotools.sh script take a list of targets

Summary:
Similar to what the build_cmake.sh script works, arguments passed to
the build_autotools.sh script are a list of targets to build.

Test Plan: Run the CI build-autotools build plan.

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6686