Add support for power supply off when it should be on

If the power good bit indicates false, or the UNIT_IS_OFF bit is on,
create an error log and attach STATUS_WORD, STATUS_INPUT, STATUS_VOUT,
STATUS_IOUT, and MFR_SPECIFIC values to the metadata. The combination of
those PMBus command results should give an indication as to why the
power supply has turned off.

Change-Id: I692a8fdeac3fe208a5eb70964db7b5094cfb587c
Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
diff --git a/xyz/openbmc_project/Power/Fault.errors.yaml b/xyz/openbmc_project/Power/Fault.errors.yaml
index 6911753..4f270e4 100644
--- a/xyz/openbmc_project/Power/Fault.errors.yaml
+++ b/xyz/openbmc_project/Power/Fault.errors.yaml
@@ -2,6 +2,8 @@
   description: The power supply has indicated an input or under voltage fault condition.
 - name: PowerSupplyInputFault
   description: The power supply has indicated an input fault or warn condition.
+- name: PowerSupplyShouldBeOn
+  description: The power supply indicated that it is not on when it should be.
 - name: Shutdown
   description: A power off was issued because a power fault was detected