drm/xe: Limit CONFIG_DRM_XE_SIMPLE_ERROR_CAPTURE to itself.

There are multiple kind of config prints and with the upcoming
devcoredump there will be another layer. Let's limit the config
to the top level functions and leave the clean-up work for the
compilers so we don't create a spider-web of configs.

No functional change. Just a preparation for the devcoredump.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>