echotest: Added support for DPDK PMD backend
echotest: Added support for DPDK PMD backend

 - Fixed the IP addresses swapping.
 - Added cmdline parameters to choose between virtio and DPDK tests.

Signed-off-by: Vlad Zolotarov <976c0f8d0852ed6439ad273880b400a75a7c41d0@cloudius-systems.com>

acbellini/scylla,asias/scylla,scylladb/seastar,avikivity/scylla,shyamalschandra/seastar,justintung/scylla,linearregression/scylla,stamhe/seastar,bzero/seastar,koolhazz/seastar,capturePointer/scylla,raphaelsc/scylla,wildinto/scylla,respu/scylla,linearregression/scylla,syuu1228/seastar,dwdm/seastar,glommer/scylla,glommer/scylla,joerg84/seastar,koolhazz/seastar,dreamsxin/seastar,stamhe/seastar,syuu1228/seastar,joerg84/seastar,duarten/scylla,aruanruan/scylla,leejir/seastar,wildinto/scylla,acbellini/seastar,bzero/seastar,shyamalschandra/seastar,avikivity/seastar,gwicke/scylla,shyamalschandra/seastar,bowlofstew/seastar,cloudius-systems/seastar,acbellini/seastar,wildinto/seastar,respu/scylla,xtao/seastar,guiquanz/scylla,xtao/seastar,cloudius-systems/seastar,ducthangho/imdb,stamhe/scylla,kjniemi/scylla,bzero/seastar,rluta/scylla,sjperkins/seastar,dwdm/scylla,eklitzke/scylla,tempbottle/seastar,scylladb/scylla,linearregression/seastar,tempbottle/scylla,leejir/seastar,slivne/seastar,tempbottle/seastar,scylladb/scylla-seastar,kjniemi/scylla,shaunstanislaus/scylla,respu/scylla,raphaelsc/seastar,senseb/scylla,duarten/scylla,norcimo5/seastar,joerg84/seastar,raphaelsc/seastar,raphaelsc/seastar,ducthangho/imdb,jonathanleang/seastar,guiquanz/scylla,sjperkins/seastar,tempbottle/scylla,flashbuckets/seastar,scylladb/scylla-seastar,stamhe/scylla,justintung/scylla,senseb/scylla,mixja/seastar,raphaelsc/scylla,scylladb/scylla,mixja/seastar,wildinto/seastar,scylladb/scylla,flashbuckets/seastar,jonathanleang/seastar,capturePointer/scylla,flashbuckets/seastar,gwicke/scylla,mixja/seastar,kangkot/scylla,dwdm/seastar,stamhe/scylla,anzihenry/seastar,capturePointer/scylla,avikivity/scylla,shaunstanislaus/scylla,bowlofstew/scylla,raphaelsc/scylla,slivne/seastar,rentongzhang/scylla,dreamsxin/seastar,chunshengster/seastar,wildinto/scylla,chunshengster/seastar,scylladb/scylla,printedheart/seastar,kjniemi/seastar,rluta/scylla,kjniemi/seastar,aruanruan/scylla,dwdm/scylla,phonkee/scylla,cloudius-systems/seastar,acbellini/seastar,shaunstanislaus/scylla,rluta/scylla,gwicke/scylla,bowlofstew/scylla,norcimo5/seastar,dwdm/scylla,bowlofstew/seastar,eklitzke/scylla,senseb/scylla,xtao/seastar,victorbriz/scylla,glommer/scylla,kangkot/scylla,chunshengster/seastar,kangkot/scylla,hongliangzhao/seastar,bowlofstew/seastar,bowlofstew/scylla,anzihenry/seastar,stamhe/seastar,acbellini/scylla,jonathanleang/seastar,kjniemi/seastar,slivne/seastar,kjniemi/scylla,dreamsxin/seastar,sjperkins/seastar,avikivity/scylla,rentongzhang/scylla,guiquanz/scylla,duarten/scylla,avikivity/seastar,linearregression/scylla,leejir/seastar,avikivity/seastar,tempbottle/seastar,anzihenry/seastar,scylladb/seastar,rentongzhang/scylla,eklitzke/scylla,norcimo5/seastar,koolhazz/seastar,printedheart/seastar,scylladb/scylla-seastar,victorbriz/scylla,ducthangho/imdb,asias/scylla,scylladb/seastar,hongliangzhao/seastar,victorbriz/scylla,acbellini/scylla,linearregression/seastar,syuu1228/seastar,phonkee/scylla,tempbottle/scylla,hongliangzhao/seastar,linearregression/seastar,aruanruan/scylla,justintung/scylla,wildinto/seastar,asias/scylla,phonkee/scylla,printedheart/seastar,dwdm/seastar