The GSCCS has its own enable and mask registers. The interrupt identity
for the GSCCS shows OTHER_CLASS instance 6.

Bspec: 54029, 54030
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20230817201831.1583172-4-daniele.ceraolospurio@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>