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.cpp b/pmbus.cpp
index b68f6fb..6ec4965 100644
--- a/pmbus.cpp
+++ b/pmbus.cpp
@@ -62,9 +62,14 @@
             return debugPath / "pmbus" / hwmonDir;
             break;
         case Type::DeviceDebug:
+        {
             auto dir = driverName + "." + std::to_string(instance);
             return debugPath / dir;
             break;
+        }
+        case Type::HwmonDeviceDebug:
+            return debugPath / "pmbus" / hwmonDir / getDeviceName();
+            break;
     }
 }