regulators: Add inventory_path to JSON chassis obj

Add the property "inventory_path" to the "chassis" object in the JSON
configuration file.

This property will be used to create the required D-Bus association
between a voltage regulator sensor and the chassis that contains it.
This association is required by the Redfish support.

Long term, this new property will be required.  That is how it is
documented in the updated version of chassis.md.

However, it will be temporarily optional in the JSON schema and the C++
configuration file parser.  This temporary measure will be removed once
all known JSON configuration files have been updated to specify the new
property.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I45f5e8ec86be7672a33099c94c35328862ffe11b
diff --git a/phosphor-regulators/config_files/ibm_everest.json b/phosphor-regulators/config_files/ibm_everest.json
index d0fe229..014815a 100644
--- a/phosphor-regulators/config_files/ibm_everest.json
+++ b/phosphor-regulators/config_files/ibm_everest.json
@@ -87,7 +87,8 @@
     {
       "comments": [ "Chassis (drawer) 1",
                     "Note: Devices not defined yet" ],
-      "number": 1
+      "number": 1,
+      "inventory_path": "system/chassis"
     }
   ]
 }