lava_helper_configs: Adjusted device type

In staging.linaro.org the mps2plus device is tagged
as mps. This change updates the lava configuration
to reflect that.

Change-Id: I49c914412ea6f5d97ff8441828dc840486061ccb
Signed-off-by: Minos Galanakis <minos.galanakis@linaro.org>
1 file changed