util,gallium: put count in pipe_resource & sampler_view on its own cache line

util,gallium: put count in pipe_resource & sampler_view on its own cache line

This adds 60 bytes to both structures. It eliminates "False Sharing"
for atomic operations (see wikipedia).

Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11618>