anv: Use genX(set_fast_clear_state)() in transition_depth_buffer()

Simplify transition_depth_buffer() by reusing a function to update the
fast-clear value instead of open-coding that logic.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35329>
1 file changed