This reads the sgml-docbook.bak and adds the entries into sgml-docbook.cat since
this occurs out of order during shared state sysroot populate.
(From OE-Core rev: 87d68520c190007869ed1877fbb40eef23763524)
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>