I added a cross-reference to the "DISTRO_NAME" variable as it is
the long version of the distribution name.
(From yocto-docs rev: bb5638409faadb9c6a5fbca729e4e6b8a220433d)
Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>