Android and stock allwinner kernel support

I have tested a10disp with removed driver version check version check on android and it seems to work, but android has framebuffer device nodes in /dev/graphics and it has no fbset utility. Also, on some devices second framebuffer is not available, so it's i changed a10disp to work even without framebuffer at all (useful for switching scaler on lcd or when hdmi clones lcd screen). I replaced almost all errors by warnings to make it work and added checks before framebuffer ioctls. Getting layer handle moved to separate function, but it seems to be equal 0x64 on all devices, so it set to 100 when not possible to get it.