iova enum definition does not need to be defined as part of the bus API.
Move it to rte_eal.h.
With this step, rte_eal.h does not depend on rte_bus.h and rte_dev.h.
Fix existing code that was relying on these implicit inclusions.
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>