drm/i915/gen12: implement Wa_14011508470

Update code to reflect recent bspec changes

Bspec: 52890
Bspec: 53508

Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200624215723.2316-1-matthew.s.atwood@intel.com