Change the default plugin behavior in perf tests

Currently we are selectively disabling plugins by creating list of
disabled plugins for performance tests. Thanks to the new API in VPP we
can revert the logic to selectivly enable plugins. This is more stable
for future onboarding of new plugins into VPP.

Change-Id: Ibdd56d6097230d095a304bbb6984b565d9428f51
Signed-off-by: Peter Mikus <pmikus@cisco.com>