drm/i915/display: On Xe2 always enable decompression with tile4

With Xe2 always treat tile4 as if it was using flat ccs.

Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240202150602.430036-2-juhapekka.heikkila@gmail.com