Currently, we can't build meson into SDKs because we don't autogenerate
the required meson.cross file.
Enable this by using the post-relocate hooks and generating a
meson.cross file based on the SDK environment passed into the
post-relocate hook.
(From OE-Core rev: aabb846b165fec218024a7a57f3c9fdaa2514179)
Signed-off-by: Martin Kelly <mkelly@xevo.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
