eal: remove unused config fields

eal: remove unused config fields

There is no need for a 'magic' field in struct rte_config, as this part of the
structure is local to each process. All threads of a process are synchronised
because of the run_once atomic.
So remove this field, as it is only adding confusion when reading code that
references 'magic' field from struct rte_mem_config.

Besides, there is no reference about the 'version' field, so remove it as well.

Signed-off-by: David Marchand <david.marchand@6wind.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>