STM32: Fix restriction on GPIO clock enables for F407 Discovery board

[hierophect]

Also expanded for F405 SoC definition, for the possible future case a F405 board with the expanded pins is added. Resolves #2679.

[tannewt]

This is good for now. Later we'll want to enable each GPIO on first use to save power. Thanks!

[hierophect]

@tannewt maybe that would be best added as a new utility in microcontroller/Pin.c? Something like "port_on" and "port_off" that you'd call in every construct and de-init/reset function, respectively. "port_on" would check if no pins are active and turn the port clock on if not, "port_off" would do the opposite.

[tannewt]

Do we need it outside of DigitalInOut? The GPIO clocks are only used by it I'd think.

[hierophect]

@tannewt no you need them for anything that uses a pin, they're included in every ST msp function for every peripheral.

[tannewt]

Ok, sounds good to factor it out into microcontroller/Pin.c. Could it be in claim_pin?

[hierophect]

Probably? I can't think of any edge cases off the top of my head where that wouldn't be enough.