drm/xe: Reformat xe_guc_regs.h

Reformat the GuC register header according to the same rules used by
other register headers:
 - Register definitions are ordered by offset
 - Value of #define's start on column 49
 - Lowercase used for hex values

No functional change.

This header has some things that aren't directly related to register
definitions (e.g., number of doorbells, doorbell info structure, GuC
interrupt vector layout, etc.  These items have been moved to the bottom
of the header.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20230602235210.1314028-1-matthew.d.roper@intel.com


Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>