[dts] [PATCH V2] framework/pmd_output:start_testpmd interface support expected params

[Tu, Lijuan]

> v1:
> In DPDK 9af79db20f4cf,when launch virtio-user testpmd as server mode,  virtio-
> user server side testpmd expected character will be 'wait for client side
> started...', after client side started, it change to 'testpmd>'.
> 
> v2:
> Modify patch comments style issues.
> 
> Signed-off-by: Ling Wei <weix.ling at intel.com>

Applied, thanks