Miniscope initialization might be incomplete

[aacuevas]

After reviewing Python480 documentation, there is a possibility our pll-enabling method is not correct.
Ideally, this should be part of the initialization sequence done by the AtMega mcu. However, we are just enabling the PLL in a completely out-of-sequence way.
The correct method would be to follow the soft-reset sequence and then power-up again with the correct settings.

Tests would be interesting to see if such an approach has any stability gains.