panfrost: Don't lie about Z/S formats
Only Z24S8 is properly supported right now, so let's be careful. Fixes a number of issues relating to improper Z/S handling. The most obvious is depth buffers with incorrect strides, which manifests in truly bizarre ways and can happen commonly with FBOs.
Fixes WebGL (Aquarium runs, etc).
Signed-off-by: Alyssa Rosenzweig alyssa.rosenzweig@collabora.com