zink: pre-hash gfx-pipeline-state

Store a hash in `zink_gfx_pipeline_state` to keep track of state
changes and avoid to recompute it when the state has not changed.

Signed-off-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Reviewed-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6061>
4 files changed