setup_board & make_chroot: make.conf.user content

Shift the responsibility of filling out the default make.conf.user
content from setup_board to make_chroot. make.conf.user is a chroot
file, its creation is out of place in setup_board.

BUG=chromium:893748
TEST=precq

Change-Id: Iaa6ea07af23d03dc2862bb0a6902d62434789a98
Reviewed-on: https://chromium-review.googlesource.com/1410046
Commit-Ready: Alex Klein <saklein@chromium.org>
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed