setup_board: Port to chromite.

BUG=chromium:893748
TEST=`setup_board --board=reef` works.
TEST=`build_packages --board=reef` still works.
TEST=New unit tests, run_tests.

Change-Id: I682edf6c50662031d7e99e1387deeef5eaaa5a2f
Reviewed-on: https://chromium-review.googlesource.com/1407459
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: LaMont Jones <lamontjones@chromium.org>
diff --git a/scripts/cros_generate_sysroot.py b/scripts/cros_generate_sysroot.py
index 8140718..867f015 100644
--- a/scripts/cros_generate_sysroot.py
+++ b/scripts/cros_generate_sysroot.py
@@ -75,7 +75,7 @@
   def _InstallToolchain(self):
     # Create the sysroot's config.
     sysroot = sysroot_lib.Sysroot(self.sysroot)
-    sysroot.WriteConfig(sysroot.GenerateBoardConfig(self.options.board))
+    sysroot.WriteConfig(sysroot.GenerateBoardSetupConfig(self.options.board))
     toolchain.InstallToolchain(sysroot, configure=False)
 
   def _InstallKernelHeaders(self):