[Fuego] Support all LTP related tests in Fuego

[Liu, Wenlong]

Hi,

As is said in the title of this mail, which is the best way to support all LTP related tests in Fuego? 

The LTP tests are complicated and wide. So, I just added another single testplan named "testplan_ltp.json" 
which is supposed to include all LTP related tests.
But I wonder if Fuego thinks at the same way or don't want to put all LTP related tests in.

Any suggestions or criticisms will be accepted.

Best Regards
Liu