regulators: Add phase faults to ErrorHistory

Add the new N and N+1 phase fault errors to the ErrorHistory class.

Update the gtests to test for the new phase fault error types.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: Ief9482219cfa8940f26a752dce9965b6c0c257e7
diff --git a/phosphor-regulators/src/error_history.hpp b/phosphor-regulators/src/error_history.hpp
index 8a2a011..f5afdae30 100644
--- a/phosphor-regulators/src/error_history.hpp
+++ b/phosphor-regulators/src/error_history.hpp
@@ -36,7 +36,9 @@
     internal = 3,
     pmbus = 4,
     writeVerification = 5,
-    numTypes = 6
+    phaseFaultN = 6,
+    phaseFaultNPlus1 = 7,
+    numTypes = 8
 };
 
 /**