panfrost: Enable FP16 by default

I see no reason to hide this. The small hit in cycle count is offset in
practice by the increase in thread count. So let's ship it and get some
testing.

If this regresses a workload:

1. Open an issue on the tracker and attach an apitrace.
2. In the meantime set PAN_MESA_DEBUG=nofp16 to override.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5960>
2 files changed