psu-ng: Refactor input fault detection

Split off input fault checking of STATUS_WORD into its own function.

Change-Id: I72a299ec1e905c9d59460b37f594997eee124e27
Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
diff --git a/phosphor-power-supply/power_supply.hpp b/phosphor-power-supply/power_supply.hpp
index 1d1e105..2ceac89 100644
--- a/phosphor-power-supply/power_supply.hpp
+++ b/phosphor-power-supply/power_supply.hpp
@@ -496,6 +496,14 @@
     void analyzeCMLFault();
 
     /**
+     * @brief Examine STATUS_WORD for INPUT bit on.
+     *
+     * "An input voltage, input current, or input power fault or warning has
+     * occurred."
+     */
+    void analyzeInputFault();
+
+    /**
      * @brief Examine STATUS_WORD for temperature fault.
      */
     void analyzeTemperatureFault();