drm/i915/dg1: make Wa_22010271021 permanent

Just like for rkl and tgl, this should be permanent as well for dg1
instead just for A0. The commit making it permanent for those platforms
ended up "racing" with the commit adding the DG1 WAs, so now fix that up.

v2: Add "tgl,dg1" to WA comment (Matt)

Cc: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201027043228.696518-3-lucas.demarchi@intel.com