Valentin David authored Mar 31, 2018 and Javier Jardón committed Apr 03, 2018

It does not make sense to be any other value that target_arch.

* sdk/project.conf: Remove bootstrap_target_arch options.

* .gitlab-ci.yml,
* README.md: Remove use of bootstrap_target_arch.

* sdk/elements/bootstrap-junction.bst: Forward target_arch
option instead of bootstrap_target_arch options.