Upgrade Exception of RK3566/RK3568

Abigai3

This is a helpful rundown of potential issues when flashing firmware on RK3566/RK3568 boards. I've definitely bricked a device or two in my time by skipping a step. The note about the Nor Flash size limitation is particularly important! Makes me think about how efficient game developers have to be, squeezing incredible visuals and gameplay into limited storage, like the folks who created Snow Rider 3D. Erasing the flash before attempting again seems like solid advice, worth remembering!