dpdk: Testpmd forwarding mode changes in v16.07

dpdk: Testpmd forwarding mode changes in v16.07

Testpmd forwarding mode mac_retry was obsoleted in DPDK v16.07.
Retry option is supported by multiple forwarding modes now.
Former "mac_retry" mode can be replaced by "mac retry" construct.

JIRA: VSPERF-333

Change-Id: I1563427985966264f07d10b1a8351784fe999d74
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: <bmichalo@redhat.com>