RDS: Add rds.h to exported headers list

Also, a number of changes were made based on the assumption that
rds.h wasn't exported, so roll these back.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 626b629..c7fbf29 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -302,6 +302,7 @@
 header-y += radeonfb.h
 header-y += random.h
 header-y += raw.h
+header-y += rds.h
 header-y += reboot.h
 header-y += reiserfs_fs.h
 header-y += reiserfs_xattr.h