Add inventory path metadata to host event log entry

The ESEL data contains sensor number to related to the event. The
generated code maps sensor number to inventory path. The inventory
path is added as metadata to the log entry for the admin to figure
out the inventory affected by the system event.

The generated header for Host event exception type is generated in the
org/open_power/Host/Event/error.hpp. Phosphor repositories should not
include open power specific header files. The eventual plan to is to
move the code to add ESEL to an OEM repo, till then we would check in
the header file in the repo. TODO: openbmc/openbmc#1658

The elog-errors.hpp is checked in for the CI to pass.
TODO: openbmc/openbmc#1772 issue would take care, so that CI
passes without the checking in elog-errors.hpp.

Resolves openbmc/openbmc#1920

Change-Id: I31d68de475ef84b8755c5de6d7ce6d311dd32214
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/error-HostEvent.hpp b/error-HostEvent.hpp
new file mode 100644
index 0000000..f8abf21
--- /dev/null
+++ b/error-HostEvent.hpp
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <sdbusplus/exception.hpp>
+
+namespace sdbusplus
+{
+namespace org
+{
+namespace open_power
+{
+namespace Host
+{
+namespace Event
+{
+namespace Error
+{
+
+struct Event final : public sdbusplus::exception_t
+{
+    static constexpr auto errName = "org.open_power.Host.Event.Error.Event";
+    static constexpr auto errDesc =
+            "A host system event was received";
+    static constexpr auto errWhat =
+            "org.open_power.Host.Event.Error.Event: A host system event was received";
+
+    const char* name() const noexcept override;
+    const char* description() const noexcept override;
+    const char* what() const noexcept override;
+};
+
+} // namespace Error
+} // namespace Event
+} // namespace Host
+} // namespace open_power
+} // namespace org
+} // namespace sdbusplus
+