pan/bi: Handle info.fs.untyped_color_outputs on Valhall

pan/bi: Handle info.fs.untyped_color_outputs on Valhall

Colour outputs in TGSI are untyped so we have to ignore the register format on
the store_output. Luckily, Valhall gives us the auto32 escape hatch to deal with
it, and Bifrost doesn't care anyway. This will avoid regressions from native int
output without corrupting the compiler for GLSL and SPIR-V shaders that are
well-typed.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17841>