[dts] dts can not support one more different nics test in one configuration file

[Tang, HaifengX]

Hi all:
Recently , I found that our dts  cannot support  one more different nics  test  in one configuration file.
Such as the following configuration:

[Execution1]
crbs=10.239.128.128
drivername=igb_uio
test_suites=
    pmd,
    ipfrag,

targets=
    x86_64-native-linuxapp-gcc
parameters=nic_type=kawela_4:func=true

[Execution2]
crbs=10.239.128.128
drivername=igb_uio
test_suites=
    pmd,
    ipfrag,
targets=
    x86_64-native-linuxapp-gcc
parameters=nic_type=springville:func=true
Thanks,
Haifeng