Documentation: Add direntry for info format

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>

qemu-doc.texi

@@ -6,6 +6,12 @@
 @paragraphindent 0
 @c %**end of header
 
+@ifinfo
+@direntry
+* QEMU: (qemu-doc).    The QEMU Emulator User Documentation.
+@end direntry
+@end ifinfo
+
 @iftex
 @titlepage
 @sp 7

qemu-tech.texi

@@ -6,6 +6,12 @@
 @paragraphindent 0
 @c %**end of header
 
+@ifinfo
+@direntry
+* QEMU Internals: (qemu-tech).   The QEMU Emulator Internals.
+@end direntry
+@end ifinfo
+
 @iftex
 @titlepage
 @sp 7