dpdk: Support new way of DPDK configuration in ovs-vswitchd

dpdk: Support new way of DPDK configuration in ovs-vswitchd

Configuration of DPDK options in ovs-vswitchd has changed.
Previously used option --dpdk was deprecated and all DPDK
related options have to be configured through ovsdb via ovs-vsctl
calls. VSPERF was modified to detect and use correct version
of DPDK configuration. New configuration options should
be put into VSWITCHD_DPDK_CONFIG dictionary.
VSPERF classes specific to OVS were refactored.

Change-Id: Ia3fad5906221439f477638f1f9734289dbf737bb
JIRA: VSPERF-291
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: Brian Castelli <brian.castelli@spirent.com>