Use delay from the HAL crate

[rnestler]

Why did you not replace sleep everywhere?

You probably mean this

The thing is, during clock setup the clock is not yet setup, so the HAL delay function would not work as expected. What I really wan't to do is:

1. Move clock initialization into HAL crate
2. Delay for a certain amount of instructions at that point (the for loop with nop doesn't really guarantee how many instructions are executed, since it depends on various things like debug vs. release)

[dbrgn]

Ah, sounds sensible :slightly_smiling_face: