drm/xe: Delete unused register from xe_regs.h

Register SOFTWARE_FLAGS_SPR33 is unused; therefore, delete it.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240715105555.2220444-2-himal.prasad.ghimiray@intel.com


Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>