drm/xe: Move xe_gpu_commands.h file to instructions/

All other files with commands definitions are in instructions/
folder. Move xe_gpu_commands.h also there.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240508174856.1908-1-michal.wajdeczko@intel.com