drm/i915/guc/slpc: Run SLPC selftests on all tiles

Run slpc selftests on all tiles

Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220923110043.789178-2-riana.tauro@intel.com