The Yocto Project documentation was migrated to Sphinx. Let's remove
the deprecated DocBook files.
(From yocto-docs rev: abdb6b6bdfef3dc8e8cc13779e44a8d6df903469)
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
(cherry picked from commit 28fb0e63b2fbfd6426b00498bf2682bb53fdd862)
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>