Now that we see warnings if LAYERSERIES_COMPAT is unset, the auto generated
code from devtool needs to set this to avoid warnings which break
various tests.
(From OE-Core rev: f65ebfeda0bfbac78e4a2a6609ba654ca38a8b0e)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>