Add PMBus device hwmon debug access type

This can be used to find a file in:
/sys/kernel/debug/pmbus/hwmonX/<device type>

For example: /sys/kernel/debug/pmbus/hwmon3/cffps1

Change-Id: Ifd9ae3a58f9097c89ebf80e3e19a180962968f0f
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/pmbus.hpp b/pmbus.hpp
index 9ab57c0..89274dc 100644
--- a/pmbus.hpp
+++ b/pmbus.hpp
@@ -88,17 +88,15 @@
 }
 
 /**
- * If the access should be done in the base
- * device directory, the hwmon directory, the
- * pmbus debug directory, or the device debug
- * directory.
+ * Where the access should be done
  */
 enum class Type
 {
-    Base,
-    Hwmon,
-    Debug,
-    DeviceDebug
+    Base,             // base device directory
+    Hwmon,            // hwmon directory
+    Debug,            // pmbus debug directory
+    DeviceDebug,      // device debug directory
+    HwmonDeviceDebug  // hwmon device debug directory
 };
 
 /**