psu-ng: Add code to detect VOUT_OV_FAULT

If the output voltage hits an overvoltage condition, the VOUT_OV_FAULT
bit (bit 5 of STATUS_WORD low byte) should turn on. The PMBus spec
indicates that VOUT fault/warning (bit 7 high byte) and VOUT_OV_FAULT
are associated with status in the STATUS_VOUT command response.

Check for VOUT_OV_FAULT after check for VIN_UV_FAULT, create error if
the fault is indicated.

Change-Id: Ia68b4f986393f0ba0184401deb29b4f5d25a2ed0
Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
diff --git a/pmbus.hpp b/pmbus.hpp
index 43d7dd8..1867e6b 100644
--- a/pmbus.hpp
+++ b/pmbus.hpp
@@ -171,6 +171,8 @@
                              Type type) = 0;
     virtual void findHwmonDir() = 0;
     virtual const fs::path& path() const = 0;
+    virtual std::string insertPageNum(const std::string& templateName,
+                                      size_t page) = 0;
 };
 
 /**
@@ -352,8 +354,8 @@
      *
      * @return string - the new string with the page number in it
      */
-    static std::string insertPageNum(const std::string& templateName,
-                                     size_t page);
+    std::string insertPageNum(const std::string& templateName,
+                              size_t page) override;
 
     /**
      * Finds the path relative to basePath to the hwmon directory