panfrost: Prepare things to get rid of panfrost_shader_state.tripipe

panfrost: Prepare things to get rid of panfrost_shader_state.tripipe

panfrost_shader_state.tripipe is used as a template for shader_meta
desc emission, but shader_meta desc preparation time should be negligible
compared to desc emission time (remember we are writing to non-cacheable
memory here). Let's prepare for generating the the shader_meta desc
entirely at draw time by adding the necessary fields to
panfrost_shader_state.

Note that we might brink back some sort of shader_meta desc caching at
some point, but let's simplify things a bit for now.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4083>