elog-errors: remove generated file

Since we use meson subprojects to build this repository outside of
Yocto, there is no need to carry along a pre-generated elog-errors
file anymore.  Remove it and ensure all code is using the real one
from phosphor-logging.

The Software.Image errors have been moved over to
phosphor-dbus-interfaces and can be used from there.  Remove them from
this repository.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic16fdef298361a878644e989b661f6312af8a0cb
diff --git a/image_manager.cpp b/image_manager.cpp
index baa0571..4fc4f8e 100644
--- a/image_manager.cpp
+++ b/image_manager.cpp
@@ -11,7 +11,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
-#include <elog-errors.hpp>
+#include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/lg2.hpp>
 #include <xyz/openbmc_project/Software/Image/error.hpp>