regulators: Implement phase_fault_detection object

Implement the new phase_fault_detection object in the JSON configuration
file.

Create gtests to test the new class.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I364281c83fbcc7fd26d2d7decb6d8338484af4e1
diff --git a/phosphor-regulators/test/meson.build b/phosphor-regulators/test/meson.build
index f036dbb..3dc46f4 100644
--- a/phosphor-regulators/test/meson.build
+++ b/phosphor-regulators/test/meson.build
@@ -14,6 +14,7 @@
     'exception_utils_tests.cpp',
     'ffdc_file_tests.cpp',
     'id_map_tests.cpp',
+    'phase_fault_detection_tests.cpp',
     'phase_fault_tests.cpp',
     'pmbus_error_tests.cpp',
     'pmbus_utils_tests.cpp',