hwmon: docs: Extend inspur-ipsps1 title underline

Sphinx is generating a build warning as the title underline
of this file is too short.

Signed-off-by: Adam Zerella <adam.zerella@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/Documentation/hwmon/inspur-ipsps1.rst b/Documentation/hwmon/inspur-ipsps1.rst
index 2b871ae..292c0c2 100644
--- a/Documentation/hwmon/inspur-ipsps1.rst
+++ b/Documentation/hwmon/inspur-ipsps1.rst
@@ -1,5 +1,5 @@
 Kernel driver inspur-ipsps1
-=======================
+===========================
 
 Supported chips: