tc-testing: add test for testing ife type

This patch adds a new testcase for the IFE type setting in tc. In case
of user specified the type it will check if the ife is correctly
configured to react on it. If it's not specified the default IFE type
should be used.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>