radv: fix enabling adjust_frag_coord_z and apply per-pipeline

radv: fix enabling adjust_frag_coord_z and apply per-pipeline

Fossilize always enables all supported extensions, that means that
adjust_frag_coord_z would always be enabled on RDNA2, even if the
application doesn't enable it. The pipeline key would then be different
and precompilation wouldn't work. Move this per-pipeline since we can
know if VRS will be used.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15444>