remove code duplication in tempest/config.py
remove code duplication in tempest/config.py

tempest/config.py has many simliar tiny functions for register_*_opts.
We should remove the code duplication to providing a common function.

Change-Id: Ie8facc21a2d8a1e27687b1182a3db9f98bc1a05e
Closes-Bug: #1236498

xbezdick/tempest,eggmaster/tempest,hpcloud-mon/tempest,hayderimran7/tempest,openstack/tempest,izadorozhna/tempest,masayukig/tempest,armando-migliaccio/tempest,Mirantis/tempest,cisco-openstack/tempest,roopali8/tempest,armando-migliaccio/tempest,ebagdasa/tempest,afaheem88/tempest,Vaidyanath/tempest,varunarya10/tempest,pandeyop/tempest,manasi24/jiocloud-tempest-qatempest,danielmellado/tempest,redhat-cip/tempest,adkerr/tempest,jamielennox/tempest,bigswitch/tempest,zsoltdudas/lis-tempest,tonyli71/tempest,jaspreetw/tempest,rzarzynski/tempest,ntymtsiv/tempest,FujitsuEnablingSoftwareTechnologyGmbH/tempest,pczerkas/tempest,akash1808/tempest,pandeyop/tempest,cloudbase/lis-tempest,xbezdick/tempest,LIS/lis-tempest,yamt/tempest,CiscoSystems/tempest,flyingfish007/tempest,redhat-cip/tempest,sebrandon1/tempest,manasi24/tempest,JioCloud/tempest,vmahuli/tempest,vmahuli/tempest,rakeshmi/tempest,tudorvio/tempest,Vaidyanath/tempest,itskewpie/tempest,yamt/tempest,JioCloud/tempest,dkalashnik/tempest,CiscoSystems/tempest,queria/my-tempest,jaspreetw/tempest,cloudbase/lis-tempest,zsoltdudas/lis-tempest,afaheem88/tempest,itskewpie/tempest,alinbalutoiu/tempest,neerja28/Tempest,hayderimran7/tempest,queria/my-tempest,masayukig/tempest,Juraci/tempest,afaheem88/tempest_neutron,Juraci/tempest,openstack/tempest,ntymtsiv/tempest,vedujoshi/os_tempest,adkerr/tempest,dkalashnik/tempest,nunogt/tempest,nunogt/tempest,rakeshmi/tempest,vedujoshi/tempest,BeenzSyed/tempest,cisco-openstack/tempest,ebagdasa/tempest,roopali8/tempest,Tesora/tesora-tempest,FujitsuEnablingSoftwareTechnologyGmbH/tempest,danielmellado/tempest,NexusIS/tempest,vedujoshi/tempest,akash1808/tempest,BeenzSyed/tempest,LIS/lis-tempest,izadorozhna/tempest,eggmaster/tempest,Lilywei123/tempest,Juniper/tempest,Mirantis/tempest,hpcloud-mon/tempest,tonyli71/tempest,sebrandon1/tempest,Juniper/tempest,manasi24/jiocloud-tempest-qatempest,vedujoshi/os_tempest,afaheem88/tempest_neutron,Tesora/tesora-tempest,pczerkas/tempest,bigswitch/tempest,manasi24/tempest,flyingfish007/tempest,NexusIS/tempest,neerja28/Tempest,tudorvio/tempest,jamielennox/tempest,varunarya10/tempest,rzarzynski/tempest,alinbalutoiu/tempest,Lilywei123/tempest