pax: remove the recipe

pax: remove the recipe

The situation with pax (vs. tar and cpio) is perfectly described here:
https://xkcd.com/927/

The only reason pax is still around, kind of, is because both POSIX and LSB
mandate it. Outside of those documents, it's not used by anyone.

Meanwhile, the upstream URI we've been taking it from went down, and rather
than seek an alternative source, I just went ahead and removed the recipe.

Signed-off-by: Alexander Kanavin <alexander.kanavin@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>