bootanimation customization

Boot logo and boot animation

u-boot doesn’t load any screen drivers..
There is an initial logo image displayed while the kernel loads. Those images are :

```
           `./kernel/logo.bmp`
```
```
           `./kernel/logo_kernel.bmp`
```

I honestly don’t know which is the correct one, I always just change them both. Format is fairly specific, so don’t get too crazy.

Once the kernel is loaded and and the android system is initializing there is a bootanimation that is shown. Documentation for the format can be found online. Source for triggering it is in a strange place in the aosp source tree (./frameworks/base/cmds/bootanimation). For the most part, once you have a bootanimation.zip that you want to use you can place it in the device folder (device/rockchip/rk312x) and use the following in your device.mk to copy it to the correct location. The system should just play it once it finds it there.

PRODUCT_COPY_FILES += device/rockchip/rk312x/bootanimation.zip:system/media/bootanimation.zip

If you are using full frame images, you can get away with about a 10fps rate. We ended up using OpenGL to get the smooth color transitions on our animations.

Bootanimation prep