drm/i915/tgl: Implement Wa_1806527549

This will whitelist the HIZ_CHICKEN register so mesa can disable the
optimizations and avoid hang when using D16_UNORM.

v2: moved to the right place and used the right function() (Chris)

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Rafael Antognolli <rafael.antognolli@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200227220101.321671-2-jose.souza@intel.com