selftests: tc-testing: add action police selftest for packets per second

Add selftest cases in action police for packets per second.
These tests depend on corresponding iproute2 command support.

Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>