drm/xe/client: Skip show_run_ticks if unable to read timestamp

RING_TIMESTAMP registers are inaccessible in VF mode.
Without drm-total-cycles-*, other keys provide little value.
Skip all optional "run_ticks" keys in this case.

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250205191644.2550879-3-marcin.bernatowicz@linux.intel.com