etnaviv: blt: stop using etna_surface

Use pipe_surface to get the necessary information for the
various clears.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35406>
1 file changed