update-info-dir maintains an index of all available
documentation in info format (the file /usr/share/info/dir).

It reads special @direntry tags in info files.

This patch (extracted from a larger patch provided by
Dirk Ullrich) adds these tags for qemu-doc.info and
qemu-tech.info.
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>