poky.yaml references are only replaced in files if they are prefixed by
& and suffixed by ;.
Let's fix the missing surrounding characters.
(From yocto-docs rev: 7ee4ba7a27acd87d8c728639d1b053d2e26c6e58)
Signed-off-by: Quentin Schulz <foss@0leil.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>