regulators: Add closeDevices() to Chassis class

Add a closeDevices() method to the Chassis class.  This will close all
devices within the chassis.  The devices should be closed when monitoring
is disabled and the system is being powered off.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I713bf470392aa49632a34fa42bf849fa2f1c4c01
diff --git a/phosphor-regulators/src/chassis.hpp b/phosphor-regulators/src/chassis.hpp
index 354da30..3fd3792 100644
--- a/phosphor-regulators/src/chassis.hpp
+++ b/phosphor-regulators/src/chassis.hpp
@@ -85,6 +85,11 @@
     void addToIDMap(IDMap& idMap);
 
     /**
+     * Close the devices within this chassis, if any.
+     */
+    void closeDevices();
+
+    /**
      * Configure the devices within this chassis, if any.
      *
      * This method should be called during the boot before regulators are