9p: Documentation updates

The kernel-doc comments of much of the 9p system have been in disarray since
reorganization.  This patch fixes those problems, adds additional documentation
and a template book which collects the 9p information.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index a452ac6..ba10f17 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -75,6 +75,7 @@
  * v9fs_fill_super - populate superblock with info
  * @sb: superblock
  * @v9ses: session information
+ * @flags: flags propagated from v9fs_get_sb()
  *
  */