cros-constants: add ARC++ variables.

Add ARC_PREFIX and ARC_VENDOR_DIR variables to the cros-constants
eclass so ebuilds that install ARC++ components can use them.

BUG=b:67717927
TEST=emerge arc-mesa

Change-Id: Ice791e6621d27afe145b2490dc7eabbf255ffd6b
Reviewed-on: https://chromium-review.googlesource.com/829979
Commit-Ready: Nicolas Norvez <norvez@chromium.org>
Tested-by: Nicolas Norvez <norvez@chromium.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Nicolas Norvez <norvez@chromium.org>
1 file changed
tree: 4f83c34440c67ab797af9f56125298d9cbad0795
  1. eclass/
  2. metadata/
  3. profiles/
  4. PRESUBMIT.cfg