PEL: Read the compatible system names property

The chassis object in the inventory has (or rather at the time of this
writing: will have) a Names property that contains a list of the
compatible system types for the current system.  An example is:
["company-systemA-4G", "company-systemA", "company"].

Add this to the DataInterface class, and remove the previous
'getSystemType' API that was there but was still stubbed out.

Also change all the calls from getSystemType() to the new call
getSystemNames(), and check against all entries in that array to see if
the desired name applies to the current system.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I86aa0c15c564153fea612f407c161dfe9041fce6
diff --git a/extensions/openpower-pels/data_interface.hpp b/extensions/openpower-pels/data_interface.hpp
index d6153b0..a2dd8f2 100644
--- a/extensions/openpower-pels/data_interface.hpp
+++ b/extensions/openpower-pels/data_interface.hpp
@@ -235,15 +235,13 @@
         getLocationCode(const std::string& inventoryPath) const = 0;
 
     /**
-     * @brief Gets the system type from Entity Manager
+     * @brief Get the list of system type names the system is called.
      *
-     * @param[in] std::string - The system type string
+     * @return std::vector<std::string> - The list of names
      */
-    virtual std::string getSystemType() const
+    virtual const std::vector<std::string>& getSystemNames() const
     {
-        // TODO, not implemented by entity manager yet, but adding now
-        // so it can be mocked.
-        return _systemType;
+        return _systemNames;
     }
 
   protected:
@@ -348,9 +346,9 @@
     std::string _motherboardCCIN;
 
     /**
-     * @brief The system type
+     * @brief The compatible system names array
      */
-    std::string _systemType;
+    std::vector<std::string> _systemNames;
 };
 
 /**