dpdk: use flags for identifying interface types

dpdk: use flags for identifying interface types

This will allow us to handle some more complex situations
like in case when hqos needs to be enabled only for some PMDs.

Change-Id: I5421a8d4cf29b8394b9e956cc4e39737dd07dbbb
Signed-off-by: Damjan Marion <damarion@cisco.com>