net/mlx4: merge flow creation and validation code

net/mlx4: merge flow creation and validation code

These functions share a significant amount of code and require extra
internal objects to parse and build flow rule handles.

All this can be simplified by relying directly on the internal rte_flow
structure definition, whose QP pointer (destination Verbs queue) is
replaced by a DPDK queue ID and other properties, making it more versatile
without increasing its size (at least on 64-bit platforms).

This commit also gets rid of a few unnecessary debugging messages.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>