sh: Create an sh debugfs root.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/system.h b/include/asm-sh/system.h
index 5145aa2..e65b6b8 100644
--- a/include/asm-sh/system.h
+++ b/include/asm-sh/system.h
@@ -146,6 +146,8 @@
 
 extern unsigned long cached_to_uncached;
 
+extern struct dentry *sh_debugfs_root;
+
 /* XXX
  * disable hlt during certain critical i/o operations
  */