regulators: Implement D-Bus configure method

The phosphor-regulators D-Bus configure method is called from a service
file when booting the BMC system.  The method is called shortly before
the regulators are enabled (turned on).

Previously the configure method did not do anything; it was a
placeholder.

This commit adds the implementation of the configure method.  The method
now configures the regulator devices in the system using the rules and
actions in the JSON config file.

Also commented out the partial implementation of the D-Bus monitor
method.  This method has not been fully implemented or tested yet.

Tested:
  * Tested phosphor-regulators application through chassison/chassisoff
    and poweron/poweroff.
  * Verified systemd state and journal messages.
  * Verified that all configuration specified in the config file was
    applied to the regulators.
  * Tested when an I2C failure occurs when configuring a regulator.
  * Verified that monitoring can be safely enabled and disabled but it
    performs no current function.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I722464a50f572c1a6e23aa13c46238d449312f31
diff --git a/phosphor-regulators/src/manager.cpp b/phosphor-regulators/src/manager.cpp
index d172f27..cbcdec4 100644
--- a/phosphor-regulators/src/manager.cpp
+++ b/phosphor-regulators/src/manager.cpp
@@ -81,13 +81,27 @@
 
 void Manager::configure()
 {
+    // Verify System object exists; this means config file has been loaded
+    if (system)
+    {
+        // Configure the regulator devices in the system
+        system->configure();
+    }
+    else
+    {
+        journal::logErr("Unable to configure regulator devices: Configuration "
+                        "file not loaded");
+        // TODO: Log error
+    }
+
     // TODO Configuration errors that should halt poweron,
     // throw InternalFailure exception (or similar) to
     // fail the call(busctl) to this method
 }
 
-void Manager::monitor(bool enable)
+void Manager::monitor(bool /*enable*/)
 {
+    /* Temporarily comment out until monitoring is supported.
     if (enable)
     {
         Timer timer(eventLoop, std::bind(&Manager::timerExpired, this));
@@ -100,6 +114,7 @@
         // Delete all timers to disable monitoring
         timers.clear();
     }
+    */
 }
 
 void Manager::timerExpired()