Raspberry Pi: Improve performance for Pi 1 and 2

[lethal-guitar]

On a Raspberry Pi 1 (model B) at stock clocks, using Raspbian Buster, I'm only getting 50 FPS at 1080p when in-game. The menus run at full speed.

When overclocking the CPU to 1 GHz and the GPU to 400 MHz, I can reach 60 FPS on my Pi 1. Reducing the resolution to 720p also works.

I don't have a Pi 2, but since it has the same default GPU clock as the Pi 1 (250 MHz), I assume that it would also need an overclock.

For reference, the Pi Zero (which handles 60 FPS easily at stock settings) runs the GPU at 400 MHz by default, CPU at 1 GHz.