Make sure there's no chance of anyone forgetting they have a recipe set
up for externalsrc; otherwise you could get confused about what is going
on. (With our default logging setup we can't make it a note because the
UI doesn't forward those; otherwise I would have used bb.note().)
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
