b9e8936bfb
This ended up being turned on in gallivm, but since we use nir_to_tgsi on
the VS and TGSI doesn't have FP16, we can't let that happen.
Fixes: f814a2449e ("llvmpipe: enable FP16 and update CL + traces piglit results.")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14403>