Clean up host_error_monitor.cpp

Clean up the remaining code that is no longer needed in the
main host_error_monitor.cpp file with the new architecture.

Change-Id: I0067e69a97e4e406a56d71480f50870f2b46c5d0
Signed-off-by: Jason M. Bills <jason.m.bills@intel.com>
diff --git a/include/host_error_monitor.hpp b/include/host_error_monitor.hpp
index 829b44f..336af02 100644
--- a/include/host_error_monitor.hpp
+++ b/include/host_error_monitor.hpp
@@ -14,6 +14,8 @@
 // limitations under the License.
 */
 #pragma once
+#include <peci.h>
+
 #include <sdbusplus/asio/object_server.hpp>
 
 #include <iostream>