drm/xe: Move GSC HECI base offsets out of register header

These offsets are only used to setup the auxiliary device BAR
information and are never used for driver read/write operations.  Move
them to the GSC HECI file where they're actually used.

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231214184659.2249559-15-matthew.d.roper@intel.com


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