Buffer compression is not usable in A stepping.

Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Clinton A Taylor <clinton.a.taylor@intel.com>
Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Clinton Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210514153711.2359617-20-matthew.d.roper@intel.com