Saul Wold provided me with more detail on this class, which
I added.
(From yocto-docs rev: 73c79f0460511039d5497bfd303cdc88f96e2fcc)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>