drm/xe/display: align framebuffers according to hw requirements

Align framebuffers in memory according to hw requirements instead of
default page size alignment.

Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241009151947.2240099-3-juhapekka.heikkila@gmail.com