drm/xe/gsc: define GSCCS for LNL

LNL has 1 GSCCS, same as MTL. Note that the GSCCS will be disabled until
we have a GSC FW defined, but having it in the list of engine is a
requirement to add such definition.

v2: rebase

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Shekhar Chauhan <shekhar.chauhan@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240419183412.1605782-2-daniele.ceraolospurio@intel.com