Handle new UCD90160 MFR_STATUS sysfs location

The 4.13 UCD90160 device driver moved the sysfs location
of the mfr_status register from
  /sys/kernel/debug/ucd9000.0/mfr_status
to
  /sys/kernel/debug/pmbus/hwmonN/ucd90160/mfr_status

The PMBus class can already handle this, just need to
change the enum to tell it where to look.

MFR_STATUS is only read when collecting metadata
on fails.

Change-Id: If4338516400f7d7acab6ec0d550417db106eea64
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/power-sequencer/ucd90160.cpp b/power-sequencer/ucd90160.cpp
index 53fff21..bc1177c 100644
--- a/power-sequencer/ucd90160.cpp
+++ b/power-sequencer/ucd90160.cpp
@@ -111,7 +111,7 @@
 
 uint32_t UCD90160::readMFRStatus()
 {
-    return interface.read(MFR_STATUS, Type::DeviceDebug);
+    return interface.read(MFR_STATUS, Type::HwmonDeviceDebug);
 }
 
 bool UCD90160::checkVOUTFaults()