DISTRO_VERSION snapshot versions use METADATA_REVISION not DATE in
hardknott and thus the default for SDK_VERSION has been updated, so
update it here as well. Additionally, fix the text so it makes sense.
(From yocto-docs rev: 7b0c4229591d6325384800137e9242c2b030e118)
Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
6a4a9e8333