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/src/meson.build b/phosphor-regulators/src/meson.build
index d9ba765..581343f 100644
--- a/phosphor-regulators/src/meson.build
+++ b/phosphor-regulators/src/meson.build
@@ -17,6 +17,7 @@
     'ffdc_file.cpp',
     'id_map.cpp',
     'journal.cpp',
+    'phase_fault_detection.cpp',
     'pmbus_utils.cpp',
     'presence_detection.cpp',
     'presence_service.cpp',