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
6 files changed