Fixes [YOCTO #11392]
Updated the section to document how to specify a branch,
tag, or revision when using devtool add with a remote
URL.
(From yocto-docs rev: 903b4a4e72908572a5f8b8c822869bbd0fe76ec9)
Signed-off-by: Kristi Rifenbark <kristi.rifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>