drm/i915/tgl: Add Wa_1808121037 to tgl.

It's not clear whether this workaround is final yet, but the BSpec
indicates that userspace needs to set bit 9 of this register on demand:

   "To avoid sporadic corruptions “Set 0x7010[9] when Depth Buffer
   Surface Format is D16_UNORM , surface type is not NULL & 1X_MSAA"

Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/2501


Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
[mattrope: Tweaked comment while applying]
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200212191728.25227-1-rafael.antognolli@intel.com