drm/i915/guc: add the GSC CS to the GuC capture list

For the GSC engine we only want to capture the instance regs.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221111001832.4144910-1-daniele.ceraolospurio@intel.com