drm/xe: Remove dump function from reg_sr

The dump function was originally added with the idea that it could be
re-used both for printing the reg-sr data and saving it to pass to GuC
via ADS. This was not used by the GuC integration, so remove it now to
give place to a new debug.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>