add chip identify code based on v4 GPL kernel code

[    3.064700] [drm:msm_gpu_pm_resume], vivante_gpu_2d
[    3.064718] IO:R f0168018 14010000
[    3.064721] IO:R f0168020 00000320
[    3.064724] IO:R f0168024 00005007
[    3.064729] vivante 0.gpu: model: 320
[    3.064734] vivante 0.gpu: revision: 5007
[    3.064741] [drm] Initialized vivante 1.0.0 20130625 on minor 1

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>