This add a description of this variable to the variable index,
and clarifies the explanations given in the devtool reference
section.
(From yocto-docs rev: 034b976addd0db6da31c4bacdbea21f2d47c00dc)
Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>