This adds the features
- periph_gpio_ll_input_pull_down:
To indicate support for input mode with internal pull down
- periph_gpio_ll_input_pull_keep:
To indicate support for input mode with internal resistor
pulling towards current level
- periph_gpio_ll_input_pull_up:
To indicate support for input mode with internal pull up
- periph_gpio_ll_disconnect:
To indicate a GPIO can be disconnected
- periph_gpio_ll_open_drain:
To indicate support for open drain mode
- periph_gpio_ll_open_drain_pull_up:
To indicate support for open drain mode with internal pull up
- periph_gpio_ll_open_source:
To indicate support for open source mode
- periph_gpio_ll_open_source_pull_down:
To indicate support for open source mode with internal pull down