Update:
-I modified retropie setup script.
-You can build and run emulationstation. Emulationstation starts only if X is running. It runs slow as hell, because it uses mesa GL libs. GLES builds will not start at the moment. Should be a emulation station problem.
-You can build and run Retroarch. At 720p the framerate drops to 40-50Hz. Shaders cannot be used (too slow). 480p or 576p should be fast enough.
-The Mali kernel module r3p0 is too old. Only one core of the MALI400MP2 dual GPU is used. If the kernel module r3p2-relxx could be build the framerate should be much better.