distributor: switch over to new API

distributor: switch over to new API

This is the main switch over between the legacy API and the new
burst API. We rename all the functions in rte_distributor.c to remove
the _v1705, and we add in _v20 in the rte_distributor_v20.c

We also rename the rte_distributor_next.h as rte_distributor.h, as
this is now the public header.

At the same time, we need the autotests and sample app to compile
properly, hence those changes are in this patch also.

Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>