anv/formats: Advertise linear sampling on depth formats
They've all supported it since either forever or Iron Lake which is
equivalent to forever for Vulkan.
From Kenneth Graunke's GitLab review:
"Linear blending of depth buffer data is usually fairly nonsense
(something's 2 meters away? another thing's 6 meters away? let's
just report 4 meters?)...but it's definitely a thing we can do, so
we may as well let apps do it, and trust them not when it doesn't
make sense."
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9110>