drm/i915/gt: Disable HiZ Raw Stall Optimization on broken gen7

When resetting CACHE_MODE registers, don't enable HiZ Raw Stall
Optimization on Ivybridge GT1 and Baytrail, as it causes severe glitches
when rendering any kind of 3D accelerated content.
This optimization is disabled on these platforms by default according to
official documentation from 01.org.

Fixes: ef99a60f ("drm/i915/gt: Clear CACHE_MODE prior to clearing residuals")
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3081
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3404
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/3071


Reviewed-By: Manuel Bentele <development@manuel-bentele.de>
Signed-off-by: Simon Rettberg <simon.rettberg@rz.uni-freiburg.de>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[Rodrigo removed invalid Fixes line]
Link: https://patchwork.freedesktop.org/patch/msgid/20210426161124.2b7fd708@dellnichtsogutkiste