modetest: add support for YUV422 and YUV444 plane format
Currently modetest supports only the YUV420 and YVU420 planar YCbCr plane formats (aka YV12 and YU12). Extend the code to add support for YUV422 / YVU422 and YUV444 / YVU444 plane formats.
Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org