panfrost: Debitfieldize mali_uniform_buffer_meta
It fits snugly in a u64, just give a macro for direct computation rather
than fudging around with bitfields. Not sure if this actually matters
with well-optimized compilers but it makes the code subjectively cleaner
so it's worth it for that if nothing else.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3838>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3838>