greybus: Export greybus debugfs folder

Add gb_debugfs_get method to access to gb_debug_root dentry,
in order to use it from other greybus modules.
Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/debugfs.c

@@ -29,3 +29,9 @@ void gb_debugfs_cleanup(void)
 	debugfs_remove_recursive(gb_debug_root);
 	gb_debug_root = NULL;
 }
+
+struct dentry *gb_debugfs_get(void)
+{
+	return gb_debug_root;
+}
+EXPORT_SYMBOL_GPL(gb_debugfs_get);

drivers/staging/greybus/greybus.h

@@ -160,6 +160,7 @@ int gb_ap_init(void);
 void gb_ap_exit(void);
 int gb_debugfs_init(void);
 void gb_debugfs_cleanup(void);
+struct dentry *gb_debugfs_get(void);
 
 extern struct bus_type greybus_bus_type;