[PATCH v2] app/test-pmd: add generic PROG action parser support

[Ajmera, Megha]

> 
> Ok, so it is predefined by the FW.
> Then shouldn't CPFL PG contain a list of supported PROGs and their arguments?
> Again, some tests/examples for it with testpmd/DTS.
> Or that's all will be the next step (patch-series)?
> 
For now, this can be independent patch since it only enable parsing in test-pmd.
With this change one can use and test PROG actions for PMDs.