clear the framebuffer

[nickdesaulniers]

I think this is "mandatory" as part of the ARM boot process: https://www.kernel.org/doc/Documentation/arm/Booting

and probably why we see rainbow colors when booting

[Wolfvak]

ideally in the future the bootloader wont even have to know anything about the screens at all, instead we relegate all the drivers (panels, backlights and display controllers) to linux itself

this can be added but it's probably not very important in the long term since it'd be removed anyway

[xerpi]

I think I didn't clear the framebuffer because it added like 1-2 secs of latency and I wanted to quickly iterate over new changes. 😅