perl: Don't change /usr/include references in docs to sysroot paths
do_configure() will no longer convert references to
/usr/include into /path/to/recipes-sysroot/usr/include
for the file "Porting/Glossary".
[YOCTO #11243]
Signed-off-by: Ooi Cinly <cinly.ooi@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>