Since https://github.com/RIOT-OS/RIOT/pull/20935 gpio_write()
uses a `bool` instead of an `int`. This does the same treatment for
`gpio_read()`.
This does indeed add an instruction to `gpio_read()` implementations.
However, users caring about an instruction more are better served with
`gpio_ll_read()` anyway. And `gpio_read() == 1` is often seen in
newcomer's code, which would now work as expected.
- Do not set an intermediate mode, prepare correct mode settings in a temporary
variable
- Consistently enabled the GPIO periph in gpio_init_af()
- Previously, STM32 F1 did not require a separate call to gpio_init() prior
to a call of gpio_init_af(), but other STM32 families did
- Now, gpio_init_af() can be used without gpio_init() consistently
- STM32 F1: Do not touch ODR for non input pins
- For input pins, this enables / disabled pull up resistors. For outputs,
this register should remain untouched (according to API doc)
