regulators: Enhance config file parser

Enhance JSON config file parser to convert relative inventory paths to
absolute form.

Tested:
Run local CI with -Dlong-tests=enabled to enable tests for
validate-regulators-config.py.

Signed-off-by: Bob King <Bob_King@wistron.com>
Change-Id: I80237a673f9c5918898db15363847722141388e6
diff --git a/phosphor-regulators/test/sensor_monitoring_tests.cpp b/phosphor-regulators/test/sensor_monitoring_tests.cpp
index 8f111eb..4d31e4e 100644
--- a/phosphor-regulators/test/sensor_monitoring_tests.cpp
+++ b/phosphor-regulators/test/sensor_monitoring_tests.cpp
@@ -102,7 +102,8 @@
         std::vector<std::unique_ptr<Rail>> rails{};
         rails.emplace_back(std::move(rail));
         std::unique_ptr<Device> device = std::make_unique<Device>(
-            "reg1", true, "/system/chassis/motherboard/reg1",
+            "reg1", true,
+            "/xyz/openbmc_project/inventory/system/chassis/motherboard/reg1",
             std::move(i2cInterface), std::move(presenceDetection),
             std::move(deviceConfiguration), std::move(rails));
         Device* devicePtr = device.get();
@@ -179,7 +180,8 @@
         std::vector<std::unique_ptr<Rail>> rails{};
         rails.emplace_back(std::move(rail));
         std::unique_ptr<Device> device = std::make_unique<Device>(
-            "reg1", true, "/system/chassis/motherboard/reg1",
+            "reg1", true,
+            "/xyz/openbmc_project/inventory/system/chassis/motherboard/reg1",
             std::move(i2cInterface), std::move(presenceDetection),
             std::move(deviceConfiguration), std::move(rails));
         Device* devicePtr = device.get();