anv: remove heuristic preferring dedicated allocations

anv: remove heuristic preferring dedicated allocations

This heuristic doesn't show much difference when you have a beafy
processor but on lower end skus, it increase the number of buffers in
the execbuffer ioctl, adding significant overhead in i915.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 4cdd3178fb ("anv: Meet CCS alignment reqs with dedicated allocs")
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26335>
(cherry picked from commit b18006397be4bfaa78a444166ae0e60b2756bf6a)