drm/i915/mtl: pass the GSC CS info to the GuC

We need to tell the GuC that the GSC CS is there.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102171047.2787951-3-daniele.ceraolospurio@intel.com